Reef Traders Outpost: Aquaria Glossary

1, 2, 3

03: [see Actinic 03]
50/50: A type of light or lighting that is 50% actinic and 50% full spectrum light for Reef aquariums, same as actinic white.
60/40: A type of light or lighting that is 60% actinic and 40% full spectrum light for Reef aquariums, similar to actinic white.
4300K: Symbol used to denote spectral output. Often used in freshwater plant tanks. [see Color Temperature]
5000K: Symbol used to denote spectral output. [see Color Temperature]
5500K: Symbol used to denote spectral output. Very close to natural sunlight. Often used in Reef tanks with Actinic lights. [see Color Temperature]
6500K: Symbol used to denote spectral output. Often MH lighting of this type is used in marine tanks, without the need for Actinic lights. [see Color Temperature]
7100K: Symbol used to denote spectral output. [see Color Temperature]

ABS: Acrylonitrile Butadiene-Styrene. A plastic material often made into tubing, safety for aquarium use in undecided.
Acid Binding: [see Buffering]
Acid Binding Capacity: [see Buffering]
Acidic: Having a pH below 7.0.
Acidity: Not commonly used, the opposite of alkalinity, the measure of the total base binding capacity.
Acclimating Fish: The process in which fish are introduced to a new tank (having different characteristics, measurable or not). It generally involves the process of removing half the water in
the bad, adding tank water and floating the sealed bags in the tank, and repeating this 3 to 4 times
every 15-20 minutes. The bags should then be emptied over a net (over the sink) to catch the fish
and it placed in the tank, so as not to introduce the store water into the tank. [see BEGINNER FAQ]
Acontia: [see Mesenterial Filaments]
Acrorhagi: A part of the structure of anemones, sacs containing nematocysts.
Acrylic: An expensive material that some fish tanks are made from, especially those which are tall, large, or oddly shaped because of its greater strength and lighter weight. It also has better
light transmission, keeps heat better, although it is easily scratched.
Actinic 03: The style of actinic lights that are used in reef aquariums because its color spectrum most closely simulates the colors used by organisms in a reef under many feet of water. It is
actually “super actinic” and has a spectrum range of 380-480 nm, with a 420 nm peak.
Actinic 05: Not to be used in aquaria. Has a spectrum range of 300-460 nm with a 365 nm peak.
Actinic Blue: An actinic bulb that has only actinic phosphor.
Actinic Lights: [see Actinic 03]
Actinic White: A combination of actinic phosphors and common phosphors for a combination of light spectrum, same as 50/50.
Activated Carbon: [see Granulated Activated Carbon]
Activated Charcoal: [see Granulated Activated Carbon]
Adding Fish: [see Acclimating Fish]
Adey, Walter: Author of “Dynamic Aquaria” and advocate of algae scrubbers. Opinions vary on his methods. [C!]
Ahermatypic: Corals without symbiotic photosynthesizing algae.
Adhesive: Any “glue” used in aquaria should be non-toxic, and also a water sealant. There are a number of commercial products for almost any material used in aquaria.
Adipose Fin: A small fin, not present on all fish, located between the caudal and dorsal fins.
Adsorption: Trapping certain molecules or ions on the surface of another substance, such as by carbon or by “resins” (which are usually plastics with molecule attached that allows it selectively
adsorb some compounds).
Aeration: The process of pumping air into the tank to increase surface agitation so as to increase the concentration of O2 in the water.
Aerobic: Occurring in the presence of oxygen, as most biological filtration by bacteria in an aquarium happens.
AFM: Aquarium Fish Magazine, a magazine, offers a subscription discount to .aquaria readers. 76107.460@compuserve.com. Especially good for beginners, the most popular.
African Rift: A variety of Cichlids come from the African Rift Lakes and they require certain water qualities.
Africans: Fish that like very hard, brackish water of the African rift lakes.
Aged Water: Water that has been allowed to sit for some time (overnight or about 24hrs), usually aerated, so the temperature becomes suitable for the tank, and chemicals such as ammonia and
chlorine off gas, as will any supersaturated O2 which is common in tap water, before being added
to the aquarium.
Aggressive Fish Control: Are probably trying to defend territory. Don’t overcrowd. Try rearranging terrain of rocks and plants in tank, so fish will re-territory, or by removing aggressive
fish temporarily to an isolation tank. Some fish will never get along with others.
Ahermatypic: Stony corals with out Zooxanthellae.
Air: A gaseous mixture of mostly nitrogen, oxygen, carbon dioxide and many other trace gasses. Required for all living things.
Air Blowers: Devices that produce a lot of air at low pressure, best for driving a large number of bubble filters in shallow tanks.
Air Compressors: Devices that produce air at high pressure, larger ones producing a lot of air at high pressure.
Air Dryers: A device that removes moisture from the air before it is used by an ozonizer, as damp air with reduce the output of the ozonizer.
Air Filters: Any device that filters the air usually going into or coming out of a Air Pump, usually using any combination of distilled water, activated carbon, micron filters or filter floss.
Air Pumps: A device that pumps air. Many sorts are available, some can be quite noisy. Used to run air powered devices such as aerators, air stones, protein skimmers and novelty air toys. They
basically fall into two types: diaphragm and cylinder.
Air Scrubbers: [see Air Filters]
Air Stones: An item attached to air tubing and air pumps that diffuses air into the tank, often made of glass, ceramic, wood, and sand stone.
Air Tubing: [see Airline Tubing]
Airline Tubing: Usually 1/4” flexible tubing for attaching air devices to air pumps. Can be cut, and heated to form tighter seals and bends. Common varieties will eventually harden, darken and
become brittle, loosing seals and potentially breaking.
Albino: A variety of a species having an almost total lack of pigment giving the skin a pale, pinkish color.
Algae: Simple plants, usually one but sometimes multi-celled, that use photosynthesis to produce energy. Generally not desired in most tanks, with the exception being Calciferous algae in reef
tanks. Most algae requires light, phosphorus, and nitrogen (especially nitrates), B12 and thiamin
to grow. Calciferous algae requires calcium.
Algae Bloom: Usually a greenish haze in the tank which is caused by any combination of too much light (especially direct sunlight), too much food, too much detritus (lack of filtration),
especially nitrate and phosphate. Can be removed by micron filters or diatom filters or will
eventually go away after excess food goes away. Warning: the bloom will severally decrease O2 levels in the tank and so the tank should be aerated well.
Algae Control: So far, the most effective way to reducing algae growth is making sure ammonia and nitrite are at 0 PPM (this is normal for all tanks) and work at reducing nitrate and phosphate
levels. Other than that, buy algae eating fish or snails, add more real plants (to use available light
and nutrients) and reduce light cycle (algae requires longer light cycle than plants), and also avoid
direct sunlight. New algae can be avoided by giving new plants a Bleach Bath.
Algae Eating Fish : In no particular order: Black sailfin Mollies, Otos, SAE, most sucker mouth cat fishes, a variety of SW fishes such as tangs.
Algae Filter: [see Algae Scrubber]
Algae Scrubber: A device that theoretically produce a more natural environment by utilizing a
large container specifically designed to support large amounts of algae. The theory goes the
algae will clean the water before it is returned to the tank. [C!]
Algae Scraper: Usually a sharp hard plastic or metal or possible a razor blade. Be careful in acrylic tanks as they scratch easily. Also make sure to dry metal completely.
Algaecide: A medication that supposedly kills algae. Usually works only for a short time, and then it returns because (bad) tank conditions promote its growth. [see Algae Control]
Alkali: (1) [see Base] (2) Material that has the characteristic of buffering pH, but preferably use Buffer.
Alkaline: [see Base]
Alkalinity: A measure of the total acid binding capacity [see Buffering] .
Alum Bath: Bathe plants for a couple days in a solution of 10 teaspoons of Alum USP per gallon (aprox. 0.2%) of water to kill snails and there eggs. [see PLANT FAQ]
Ammonia: Chemical symbol NH3, highly toxic to aquarium organisms, part of the nitrogen cycle. Even 1 PPM is toxic, keep it at 0 PPM. The ratio between ammonia and ammonium is determined
by pH and temperature, as both increase, so does the percentage of toxic ammonia. It has been
shown that ammonia/ium is the prefered source of nitrogen for most aquatic plants. At pH 7.0
almost none is in toxic ammonia form, and below pH 7.5 very little is toxic. For SW tanks at 78 F.,
at pH 8.2, 8% toxic, at pH 8.3, 10% toxic, and at 8.4, 12% toxic ammonia.
Ammonium ion: Chemical symbol NH4+, fairly toxic to aquarium organisms, part of the nitrogen cycle. [see Ammonia]
Ammoniafication: The process in which bacteria break down biological waste into ammonia. [see Nitrogen Cycle]
Amphipods: Tiny crustaceans “water fleas” often occuring in reef tanks. They make a good food supply for other creatures, and seldom cause any problems.
Amps: A measure of electrical current. Equal to volts divided by resistance in ohms.
AmQuel: A common chemical for de-toxifying ammonia, chloramine and chlorine. [C!]
Anal Fin: The fin located towards the tail fin, on the bottom of the fish.
Anaerobic: Occurring in the absence of oxygen, typically refers to bacterial activity.
Anaerobic Bacteria: Usually harmful in that they produce toxic chemicals or gasses. This usually results in a reducing process.
Anemone: A mobile invertebrate closely related to corals and jellyfish. Most have stinging tentacles, and some people have problems with them stinging corals to death. Many require
bright sunlight for their symbiotic algae (and them) to survive. Some will allow clownfish to live in
them and have a symbiotic relationship.
Angles: Pterophyllum scalare. A FW egg laying chiclid that is somewhat flattened laterally, and has largish dorsal and anal fins and comes in many colors/varieties. Is bred often and some
variations are highly prized.
Angstroms: A measure of length equal to 0.1 nm.
Anion: (1) A negatively charged ion.(2) A resin that adsorbs chemical cation used in DI water filters.
Anoxic: Oxygen-poor. [compare with Anaerobic]
Anubias: A species of plant exemplified by extreme hardiness. Most common variety is A. nana which is a low-growing, low light vine-like plant. It is very slow growing except in conditions of high
CO2 and high fertilization.
AOL: America On Line. A private computer network.
Apple Snail: [see Mystery Snail]
Aquarist and Pondkeeper: A British magazine.
Aquarium Societies: One list is available through FINS. Check the back of hobby magazines for listings also.
Aragonite: A form of CaCO3, which comprises coral skeletons and derivatives of it. It’s a good source of calcium and strontium, but not magnesium.
Archives: A collection of articles, USENET posts and other items of interest to the aquarist. They can be located at ftp.cco.caltech.edu/pub/aquaria.
Area: For circular shapes, area is Pi * radius. For rectangular shapes, is length * width.
ARP: Artificial Plankton and Rotifers, a product name.
Arowanas: A long thin fish that tends to keep to the top of the tank. Can grow to be a few feet in length, and so needs a extremely large tank (over 100 gal.)
Artemia salina: [see Brine Shrimp]
Asexual Reproduction: Reproduction found in many invertebrates in which only one individual is required. There are different types of
Astraea Snails: Astraea tectum. A small SW microalgae eating snail that is highly recommended for reef tanks. Stocking levels have been suggested on the order of 1 snail per 1 to 2 gallons.
ATM: Atmospheres, usually refers to multiples of equivalents pressures as compared to Earth’s.
Automatic Feeders: Electric devices which dispense fish food (usually pellets because flakes with disintegrate given the moisture) once or a couple times per day, usually for at least a week to up
to four weeks. [see Feeding Fish]
Autotrophic bacteria: Bacteria which produce energy using light or inorganic chemical reactions,
and which use CO2 as a carbon source. Compare with heterotrophic bacteria.

Back Filters: Generally, any type of external filter that hangs on the back of the tank. [see Power Filter]
Back-Siphon: The unfortunate possibility that any tube or pipe in the tank and terminating below the tank may siphon water back down the tube if flow is not maintained up the tube (like in the
case of a power outage).
Back Pressure: The resistance to the outflow of a pump, this will decrease flow rate of pump. Some pumps can be damaged by too much back Pressure, some need some to operate
efficiently.
Bacteria: Simple, very small organisms without a cell nucleus, which live either by absorbing food from the environment, by photosynthesizing using light, or by using some chemical reactions (i.e.
converting nitrites to nitrates) to provide energy.
Bacteria Bloom: Can be caused when aquariums are cycling, or in established tanks, due to overfeeding or excess biological material such as dead plants or fish.
Baking soda: Sodium Bicarbonate. Increases KH, and thusly pH, use sparingly. Its pKa is 6.38.
Ball Valve: A type of value for controlling water flow.
Ballast: A device that powers florescent bulbs. A few types are available and each has its own good and bad points. The ballast must match bulb wattage’s, length and current drain.
Barbels: Sensory organs, mostly found on bottom feeders, near the mouth that resemble whiskers. Low water quality, poor diet or hazardous substrate may lead to the decay of barbels
on some fish, but fixing the problem will usually help them grow back.
Base: A material having a pH above 7.0.
Base Rock: LR that is mostly encrusted algae.
Basic: Having a pH above 7.0.
Bass Wood: A wood that some air stones are made of, especially those used in protein skimmer because they produce exceptionally fine bubbles, but create a large back pressure on the air
pump, so this limits the amount of air pushed through the wood.
Bath: A method of medicating which involves placing the patient in a solution of (usually) tank water and some medication for a relatively short period of time.
Beard Algae: Named so because its looks like a beard, often on plant leaves, each strand may be up to a few centimeters in length but usually looks matted/clumped. Is common even in good
water, can be destroyed by Simazine.
Beauty Lights: Lights sold to improve display color of fish and plants, but it incorrect spectrum for plant growth. [see Light Spectrum]
Bed: Generally used to refer to a filter bed, such as the substrate in a UGF, the biological filter media in a wet/dry or the media in a power filter.
Benthic: Refers to organisms or effects that are found towards the bottom, or in the substrate.
Berlin Method: A method of reef keeping that specifies no other filtration besides that of a large protein skimmer, good circulation in the tank (no stagnant areas), a large amount of high quality
live rock (generally 2.5 lbs per gal.), proper lighting (generally 3+ watts per gallon), and very few
fish. Named after Berlin, Germany where it started.
Berliner: A reef keeper who uses the Berlin Method.
Bernoulli: As applies to aquaria, used in powerheads to draw air into the outflow of the pump, causing aeration. Says that in a fluid, as the speed of the fluid increases, the pressure drops (as
an example, air moving past your car window is at a lower pressure than the air inside your car,
due to its movement. Therefore, smoke is sucked out of the car).
Bettas: Siamese Fighting Fish, scientific name Betta splendens.
Bio Balls: A commercial biological filter media. [see Trickle Media]
Bio Load: The ‘load’ placed on filtration system by all the biological organisms in the tank.
Biogenic Decalcification: Some plants can extract CO2 from bicarbonates when levels of CO2 gas is insufficient. This precipitates carbonates and increases pH. Some plants can even extract
CO2 from carbonates, increasing pH even more.
Biological Filter: Any of a type of filters that work by supplying a constant supply of water through a media that promotes the growth of bacteria that breaks down biological waste.
Biological Filter Media: Usually has a large surface area, often with large air areas for trickle filters. Anything from Filter Floss to Bio Balls. It has been suggested a rule of thumb for
determining required amount of media is 4 sq. ft. of surface area per gallon of tank. WARNING:
when replacing the sole (or even part) of your biological filter media (commonly filter floss) you are
throwing away your bacteria and are in essence making your filter useless until bacteria re-
colonize the media, this may take some time.
Bicarbonate Ion: Chemical symbol HCO3-2. The predominate buffer in sea water. [see Carbonate Hardness]
Bivalve: Creatures such as clams that have two halves of a shell that open and close.
Black Light: A UV light in the spectral range of 310 nm to 400 nm with a 370 nm peak that is sometimes used in marine and reef tanks to accentuate the colors of fish, and especially inverts.
Black Sailfin Mollies: Known to eat algae.
Bleach Bath: A treatment that can be used on new plants to destroy algae while causing little or no harm to healthy plants. Bathe plants in a solution of 5% bleach and water for 2 minutes,
remove, rinse the plant, and bathe in another solution of chlorine remover and water.
Blood Worms: Red larvae of Chironoinidae sp., very high in protein, used as live food often also available freeze dried.
Blowers: [see Air Blowers]
Blue Green Algae: [see Cyanobacteria] [see PLANT FAQ]
Bog Plants: Plants that aren’t normally submerged all the time. Often times sold in fish stores as regular underwater plants, such as aluminum plant (Pilea cadierei), Chinese evergreen
(Aglaeonema), peace lily (Spathiphyllym) and Lycopodium (ground pine). May or may not survive
in a aquarium, usually not.
Borosilicate Glass: "Pyrex" brand glass.
Brackish Water: Water containing some salt, but less than "salt water" tanks, specific levels depend on species (such as Cichlids, Mollies, etc.) being kept. Generally brackish water has a
specific gravity between 1.004 and 1.015.
Breeding Fish: Some reproduce like rabbits, others need some coaxing, others require the plants to be aligned (or some other stroke of luck), others with never reproduce, usually because they
don’t reach sexual maturity in captivity. Refer to a reputable book or check the archives for tips
on breeding common fish.
Breeder Tank: A tank set aside for breeding fish in. Depending on the species, may or may not have a substrate, although peat is very common. Usually has plastic plants for egg layers and
hiding places. Usually has bubble filters so as not to disturb fry.
Brine Shrimp: Scientific name Artemia salina, a common crustacean used as live or freeze dried food.
Brine Shrimp Eggs: Usually, living eggs that can be hatched at home for use as live food.
British Measurements: [see UK Measurements]
Brown Algae: Diatoms, which use excess silica, or may be caused by insufficient light.
Brush Algae: Often found on plants, forming dark (it’s actually a red algae) tufts 2 to 3 mm in size.
BTU: British Thermal Unit, a measure of heat often used in reference to chillers and heaters. The amount of heat required to raise 1 pound of water 1 degree Fahrenheit.
BTW: By The Way.
Bubble Algae: [see Valonia Algae]
Bubble [Up] Filter: A type of internal filter than uses air bubbles to circulate water from the filter
media (usually a sponge) and up a tube. [see FILTER FAQ]
Bubble Nest: A floating construction of fish-created bubbles which holds their externally fertilized eggs. Usually requires very smooth slow moving water flow.
Bubbler: A device such as an airstone used as decoration or to increase surface agitation.
Buffer: A substance having the ability to neutralize acids and bases to some degree and so maintain a particular pH.
Buffering Capacity: AKA Alkalinity. The ability to maintain a pH despite additional acids, in aquaria this is predominately done by bicarbonate and carbonate, and borates and hydroxides,
although other compounds contribute to a lesser degree. Sea water has approximately 2.5 mEq/l.
Bulb: (1) The glass and connecting hardware of a light.(2) A part of some plants used to store energy as starches, appears as a underground, rounded
enlargement of the main stem.

C: [see Centigrade]
C: Chemical Symbol for Carbon.
C.A.: Coralline Algae.
Ca: Chemical symbol for Calcium.
CA Membrane: [see Cellulose Tri-Acetate]
Ca++: Chemical Symbol for Calcium ion that is a plant nutrient.
Cable Heating [System]: [see Heating Coils]
CaCl2: Chemical symbol for Calcium Chloride
CaCO3: Chemical symbol for Calcium Carbonate.
Ca(HCO3)2: Chemical symbol for Calcium Bicarbonate.
Calcareous: Containing or having to do with calcium carbonate.
Calcium: Chemical symbol Ca, but available in many molecules. A vital nutrient in reef tanks with corals and shelled critters. Sea water levels are approximately 10 mM Ca++ or 400 PPM. Many
reef tanks at kept at levels close to 500 mg/l.
Calcium Bicarbonate: Chemical symbol Ca(HCO3)2.
Calcium Carbonate: Chemical symbol CaCO3.
Calcium Chloride: Chemical symbol CaCL2, a calcium additive sometimes added to reef tanks.
Kalkwasser is preferred, but calcium chloride can be used to raise calcium levels quickly but may
cause problems with pH.
Calcium Hydroxide: [see Kalkwasser]
Calcium Reactor: A device usually used to introduce Kalkwasser into a reef aquarium. [see Kalkwasser and Reactors]
Calciferous Material: Any material used in marine or reef tanks to leach calcium carbonate into the water.
Cannibalism: The tendency or affinity for one species to consume one of its own kind, often used to mean any fish who eats another.
Canister Filter: A very efficient kind of external filter that uses a pump to propel water through the filter media, and then back to the tank, often used with tanks above 30 gals. Usually have
compartments to mechanical and chemical filtration media, may also have biological filtration, or
the ability to add a heating unit.
Canopy: [see Hood]
Ca(OH)2: Calcium Hydroxide. [see Kalkwasser]
Caps: [see End Caps]
Carbon: Chemical symbol C. Also refers to carbon filtration. [see Granulated Activated Carbon]
Carbon Dioxide: Chemical symbol CO2, a product of fish, utilized by plants during lights cycles, and produced by plants during dark cycles. More CO2 also lowers pH. Aquatic CO2 is at
equilibrium with atmospheric CO2. Most non CO2 injected aquariums have CO2 levels around 5
PPM, but plants are best raised with 10-15 PPM. [see WATER FAQ]
Carbon Dust: When a package of activated carbon is used, the dust should probably be rinsed out under room-temperature water.
Carbonate Ion: Chemical symbol CO3-2. [see Carbonate Hardness]
Carbonate hardness: A measure of bicarbonate (HCO3-) and carbonate (CO3-) ions in the water. This helps to stabilize pH. (Its pKa is 10.25.)
Carbonic Acid: Chemical symbol H2CO3.
Carnivore: Primarily eats animals or foods derived from animals.
Cartridge: Often power filters and canister filters use pre-made cartridges with either carbon, or some chemical filter.
Cat Fish: A general name for any number of species of usually bottom dwelling fish. They are usually scavengers and help to keep the tank clean, eat algae, although some are somewhat
predatory. Beware of using nets because many species have spines in that become snarled and
may damage the fish or prevent them from being removed from the net. Many are also very
sensitive to dissolved oxygen levels, and water quality in general.
Cation: (1) An ion with a positive charge.(2) A resin that adsorbs other chemical anion, used in DI water filters.
Caulerpa: Chlorophyta, a fleshy macroalgae found in SW tanks, generally avoided in Reef tanks.
Caudal Fin: The tail fin, sometimes divided into Lobes.
Caudal Penduncle: The part of the fish’s body right before the caudal fin, a slender muscular area.
cc: (1) Cubic Centimeter.(2) Counter Current [see Protein Skimmers]
CDN: [see Coil Denitrator]
Cellulose Tri-Acetate: A material of which some RO membranes are composed. [see Reverse Osmosis]
Celsius: [see Centigrade]
Centrifugal Pump: A type of water pump.
Centigrade: The metric measure of temperature, multiply by 1.8 and then add 32 to get Fahrenheit. [see Temperature]
CFM: Cubic Feet per Minute. Usually a measure of an air pump output.
CH: Carbonate Hardness.
Channeling: The effect of currents traveling through a substrate (or any media) will not flow through evenly because of resistance or clogged areas, especially through thick media or at low
flow rates.
Characins: [see Tetras]
Charcoal: This more correctly refers to common charcoal-looking substance that used to be used in place of GAC (which is more effective), but now if often used as a synonym. [see Granulated Activated Carbon]
Check Valve: A value that allows a flow in only one direction. Used to prevent back-siphon.
Chelate: A synthetic organic substance which will bind another substance (almost always an ion), often EDTA (binds calcium, magnesium, and similar ions) or DTPA. Means "held in crab-like
claws."
Chelated: Binding a mineral with a chelate to make it easier for organisms to utilize and to keep it from oxidizing into unusable forms in the presence of O2.
Chemi-Pure: A commercial product often used in marine and reef tanks as a chemical filter.
Chemical Filters: Any filter that uses chemicals to clean the water, examples of these are carbon, ozone, and any of the resins.
Chemical Filter Media: Any of the resins, carbon, or others which are usually placed inside filter bags or pads, or contained in small pouches. Some materials may have different adsorption
characteristics.
Chemicals: These are different from chemical filters, and they are often added to an aquarium to remove ammonia, chlorine, metals, as medications, or to otherwise change other characteristics
of the water. You should beware mixing them as they can sometimes have strange reactions.
These additives generally are used for quick fixes of things that have a better, more natural, long
term solutions. Also be aware that many chemicals can kill or harm your biological filter, also
GAC will remove most chemicals. Some chemicals will also stain color your water or stain the
tank’s silicon. Be sure to read the instructions carefully.
Chemoautotrophic Bacteria: Bacteria which obtain their energy from chemical reactions (usually inorganic chemical reactions such as oxidizing sulfur) and which use CO2 or other inorganic
carbon as their carbon source.
Chemoheterotrophic Bacteria: Bacteria which obtain their energy from chemical reactions (i.e. converting sugar to carbon dioxide like we do) and which use organic molecules as their carbon
source.
Chiller: A device used to keep the temperature low enough to be comfortable for the fish. Basically two types are available, those with titanium coils that are placed in sumps or other
isolated high flow areas (drop-in), and flow through types. [see FILTER FAQ]
Chinese Algae Eaters: Gyrinocheilus aymonieri. Not known to eat algae as often believed. May become territorial and aggressive when they get larger.
Chloramine: Chemical symbol Cl-NH3+. A substance composed of chlorine and ammonia which is very toxic to aquarium organisms, which is common in municipal tap water and must be
removed before adding to aquarium. Beware chlorine only removers because this will leave the
ammonia and result in dead fish. This can not be off-gassed by aeration.
Chloride: Chemical symbol Cl.
Chlorine: A substance commonly found in tap water. It can be removed by chemicals or by aging the water. It is of some toxicity to aquarium life. [C!]
Chlorophyll: The biological material in plants that do the process of photosynthesis. Similar to heme, which is the oxygen carrying portion of hemoglobin. Contains magnesium, much as heme
contains iron.
Chlorophyta: A division of green marine algae.
Cichlids: (Pronounced SICK-LID) Many show varied, interesting and complex mating and parental skills.
Circulation: Every tank needs some sort of circulation, even if it is only produced through a sponge filter, to keep detritus from getting trapped and to keep water circulating by the surface.
Different species of fish have different likes and dislikes when it comes to circulation. Greater
circulation is more important in SW tanks, especially Reef tanks.
CIS: CompuServe Information System. [see CompuServe]
Cl: Chemical symbol for Chloride.
Cleaning the Filter: A common mistake is throwing away the biological media in the filter (like the filter pad or sponge) if this is the only biological filtration in the tank. It is best, given that media is
still structurally sound, to siphon out some tank water, rinse the media in this water to remove
sediment and decomposing biological waste, and then throw out this water and return the media
to the filter. In this way, the bacteria in the media are not killed by incorrect temperature or
chlorine or other toxins in the tap water (the way it is commonly done).
Cleaning the Tank: Never ever use any chemical, soap or detergent not specifically designated for use in an aquarium, and be very careful using any of these around the fish tank (like for
cleaning glass), even spray or fumes can cause problems in the tank. Common table salt
(uniodized) can be used as an abrasive (but some fish wont like this) but it very useful when tank
is empty. Bleach can be used on empty tanks or equipment but it must be rinsed thoroughly and
de-chlorinator should be generously used to remove any remaining bleach (it shouldn’t smell
anymore) before being used.
Cloudy Water: Can be caused by a bacteria bloom or particles in the water. Usually as a result of overfeeding or lack of cleaning, although sometimes seen briefly when cycling a tank. [see Mechanical Filtration].
CO2: Chemical symbol for Carbon Dioxide. [see Carbon Dioxide]
CO2 Dosing: A system that injects CO2 into the tank to keep pH stable, usually controlled by a pH meter.
CO2 Injection: A process by (usually) compressed CO2 gas is added to the tank to supply plants during photosynthesis. Since dissolved CO2 is at equilibrium with atmospheric CO2, CO2 injection
is always fighting a losing battle. It has been suggested that a relatively closed cover over the
tank can increase close-atmospheric CO2 concentrations.
CO2 Reactor: A chamber where CO2 bubbles (from CO2 injection) are allowed to absorb into the water.
CO3-: Chemical symbol for Carbonate Ion.
Coagulant: A chemical that causes small particles to stick together so they as more easily caught in mechanical filters, often used in water clarifiers.
Co-current: A term used to describe protein skimmers that work in the following way: the flow of water and air bubbles are in the same direction.
Coelenterates: Anemones and corals.
Coil Denitrator: A device comprised of a coil of tubing that, under the right circumstance, will remove nitrate, but also has the potential to create nasty chemicals. [C!]
Coil Heater: [see Substrate Heating]
Cold Water Tanks: This may be a FW, brackish or SW tank that have much lower temperature (approximately room temp.) than tropicals. Cold water SW fish tend to be less colorful than
tropical species. You will almost certainly need a chiller since most cold water tanks are kept in
the 50-60 F range, depending on the species or habitat being simulated.
Colonies: Usually of corals or anemones, or bacteria.
Color [Enhancing] Food
Color Temperature: A measure of spectral output measured in Kelvin, as equated with a “black body” at that temperature. Over 5000K approximates sunlight. [see Cool Light, Warm Light,
Neutral Light, and Day Light]
Comets: A simpler form of goldfish, as compared to Fancy Goldfish
Community Fish: Tetras, Barbs, Danios, Rasboras, Gouramis, Angelfish, Corydorus and other small catfish, Platies, Mollies, and Swords.
Compressors: [see Air Compressor]
CompuServe: The largest private computer network, which also has an aquarium conference.
Controller: Usually a electronic test device that controls another device based on its
measurements. Example: A redox meter controlling a Ozonizer.
Cool Light: This generally refers to light from about 3600 to the low 4000’s Kelvin. It appears white to blue-white.
Cool White Bulbs: Common fluorescent lights that usually come with light fixtures for tanks and people use, are passable for fish only tanks, but tend to promote algae. A full spectrum light will
appear brighter, improve plant growth, reduce algae and make your fish look better and aren’t that
much more expensive.
Cooler: [see Chiller]
Cooling: In general, keeping the temperature in the tank low enough. Machines are available [see Chiller] , but you may also float zip lock bags of ice to cool down a tank (do this very slowly!).
Copepods: Crustaceans that, like Daphnia, swim by using their antenna. There are indicative of a healthy reef tank, and are part of the ecosystem.
Copper: Chemical symbol Cu. Often used in freshwater and marine tanks to cure ailments, but NEVER to be used in marine tanks or with invertebrates. In sea water in concentrations around
0.5 micrograms/liter, or up to 3 micro-g/l in aquaria. Tap water may contain as much as 1000
times as much.
Coral: An invertebrate that typically consists of a colony of polyps with stinging tentacles, emerging from either a hard external skeleton (hard or stony corals) or a fleshy body reinforced
internally with calcareous spicules (soft corals).
Coralline Algae: A SW tank calcareous encrusting algae in pink, purple, white, yellow, maroon and brown. It is necessary for current day reef tanks and requires plenty of light, clean water and
calcium.
Corallivores: Those organisms, such as butterflyfishes and some snails, which prey on corals.
Counter-current: A term used to describe protein skimmers that work in the following way: the flow of water is opposite the flow of air bubbles. This method is more efficient than co-current
because the air bubbles have more contact time with the water.
CFM: Cubic Feet per Minute, usually a measure of air flow.
CPM: Cubic Inches per Minute, usually a measure of air flow. Divide by 61.024 to find LPH.
Crash: What happens when an aquarium system is slightly out of balance and it builds up until a seemingly exponential decay in quality happens (much like the domino effect) usually resulting in
large losses of aquarium life.
Crepuscular: Relating to or occurring during the twilight, often relating to the activity or eating patterns of aquatic life.
CRI: Color Rendering index, a quality of lights which measures the percentage of natural sunlight’s spectrum.
Crown: The part of the plant where the main stem meets the roots. When planting the crown should be just above the substrate.
Crushed Coral: A substrate only for marine or reef tanks, which has buffering capacity and often includes some trace elements that are beneficial to SW tanks.
Crustaceans: Anthropods having a shell such as crabs and shrimp.
Cryptocorne (genus): Rosette plants found in tropical waters in Southeast Asia. Widely used in aquaria.
Crypts: [see Cryptocornes]
CTA: [see Cellulose Tri-Acetate]
cu.: Cubic or to the power of three, often written ^3, refers to volume.
Cu: Chemical symbol for Copper.
Culture: The growing or reproduction of a specimen, often used when discussing raising live food, algae, or bacteria, although sometimes with higher order organisms.
Cured: [see Cured Rock]
Cures: [see Fish Cures]
Cured [Live] Rock: Live rock that has been cycled (because of die off caused by exposure to air) and will not cause problems when added to a tank.
Curing [Live] Rock: Removing any dead or dying organisms, and macro algae like caulerpa, often using a brush and tweasers, and then cycling it.
Cyanide Poisoning: A ailment of fish caught with cyanide (illegal most places although still practiced, especially with marine fish) that usually leads to them not eating, or if they do, their
bodies are unable to digest the food and they waste away.
Cyanobacteria: Often caused by too much Iodine and too little current, and will cause problems in reef tanks. Nothing eats it, but it can be siphoned out, or treated with light doses of Maracyn [see REEF FAQ]
Cycle: [see Cycling]
Cycling: The process in which a new aquarium is started, to make it suitable for life, in which the nitrogen cycle is started. This may take from 3-6 weeks for all the bacteria to reach acceptable
levels, although if the tank in not started correctly/messed with it may never cycle correctly until
conditions are right. Some have suggested keeping the temperature at 80 F to increase bacterial
growth during this period. [see BEGINNER FAQ]
Cycling with Chemicals: You’re just making the process more difficult. If you want to speed up the process, buy or borrow some biological filter media (including gravel) from reputable source.
Cycling [Live] Rock: When adding non-cured live rock, there will be a die off because of exposure to air, and will cause increases in ammonia and nitrite for a couple weeks, possibly to toxic levels.
Cyclops: A FW crustacean sometimes used as food. May be more of a pest used live in FW tanks.
Cylinder Pump: A type of air pump that uses a cylinder and a piston, they generally produce more air and are noisier than diaphragm pumps.

DA: [see Dynamic Aquaria]
Daleco: A MO business. [see MO FAQ]
Daphnia (pulex): “Water Flea” A FW crustacean used as live or frieze dried food.
Day Light: Refers to light spectral output of 5000 Kelvin or higher. Most closely approximates true sun light.
dCH: Degrees of Carbonate hardness.
DE: [see Diatomaceous Earth]
Dead Fish: Aren’t much fun, but it happens, usually from non-natural causes and inevitable this points to some form of water quality problem. [see Euthanasia] for disposal methods.
Dead Sand: Regular sand or gravel, as compared to marine live sand.
Dead Spots: Any area of a biological filter, especially UGF, that has a lack of O2 and so promotes the growth of anaerobic bacteria.
Deaminator: A chemical that removes ammonia by converting it into a non-toxic form so it can be removed by the biological filter bed. Note that many of them contain Phosphorus. [see Water Conditioners]
Dechlorinator: A chemical that removes chlorine. Be careful *not* to only use this with tap water that contains Chloramine because it will release the Ammonia leading to a loss of aquatic life.
Note that many of them contain Phosphorus. [see Water Conditioners]
Decorations: Make sure they are non-toxic, will not leach any chemicals, and also will not absorb any chemicals.
Decorative Coral: Dead coral than is used in marine and reef tanks as decoration, often times it has been bleached and/or colored.
De-gas: Expel. [see Off Gas]
De-ionized Water: These systems use a resin to purify water. After adsorbing so much, the filter beds must be replaced (with mixed beds) or recharged (only separate bed units) using powerful
acids and bases. For FW, buffers and trace elements need to be added back to the water.
Delbeek, Charles: Aquarist and co-author of “The Reef Aquarium” (which is highly recommended) with. He advocates the Berlin method of reefkeeping.
Detritus: Organic waste in the tank
Detrivore: Organisms that consume or otherwise convert detritus, mainly off the substrate or tank bottom.
Denitrification: Refers to the conversion of inorganic nitrogen to dinitrogen by anaerobic chemoautotrophic bacteria. [see Nitrogen Cycle]
dGH: Degrees of General Hardness, commonly , multiply by 17.8 to get PPM of CaCO3.
DH: Degrees Hardness [see dGH] .
DI: De-Ionized. [see De-ionized Water]
Diameter: The internal distance between opposing walls in a tube or pipe. Twice the radius.
Diaphragms: Rubber membranes which are used in some air pumps to push the air. They most be replaced after some time. They generally produce less air but are less noisy than cylinder
pumps.
Diatom Filters: A extremely effective mechanical filter composed of diatomaceous earth powder. [see FILTER FAQ]
Diatomaceous Earth: Hard silicon skeletons of tiny single celled animals called diatoms. Apparently, this is the same material as used in swimming pool cleaners, *BUT* the swimming
pool variety contains chlorine which will harm your fish. [see Diatom Filters]
Diet: It is best to feed your aquarium fauna the widest variety of foods you can in order to maintain their health.
Diffuser: Any device which diffuses air, water or anything else in order to keep it from concentrating in one area.
Digital Test Kits: [see Electronic Test Kits]
Dimmers: Devices for either manually or automatically brightening and dimming lights so provide a progressive change in lighting so its more natural, reduces stress on fish, especially in bright
lighting conditions.
DIN: Dissolved Inorganic Nitrogen, a term representing the presence of ammonia, nitrite, and nitrate.
DIP: Dissolved Inorganic Phosphorus.
Dinitrogen: Chemical symbol N2. The last stage of the nitrogen cycle. This takes a gaseous form and off gasses from the aquarium. Very few plants are able to use nitrogen in this form, it is
non-toxic is aquatic life.
Disapearing Fish: This happens usually with small, marine moreso than FW, fish in a mature tank. If the fish becomes sick and weak and falls prey to another fish, other fish will usually
devore much of the fish. Once it falls to the substrate, small organisms and bacteria (this is
especially true of reef tanks) will have their way with it and it will often be gone by morning.
Discus: A somewhat large, roundish fish from So. America that like soft water. They are often highly prized and certain variations pricey.
Disease: Will all diseases, you should be careful not to spread it by using contaminated nets, gravel siphons, etc. Carbon and other chemical filters (including skimmers and ozonizers) will
remove most medications and should be removed during treatment.
Distilled Water: A method for creating very pure water by controlled evaporation and condensation. It can be bought in stores and is very useful, especially for make up water for
evaporation.
Diurnal: Relating to or occurring during the day, often relating to the activity or eating patterns of aquatic life.
[DIY]: Symbol used in newsgroup subject lines to denote that the topic concerns DIY projects.
DIY: Do It Yourself, home made, a device or system that is built by the hobbyist.
DIY Live Food: Raising and breeding your very own live food. [see BEGINNER FAQ]
DIY Tanks and Hoods: It’s possible to build your own tanks and hood, stands, etc. [see ARCHIVES]
DIY Vegetable Fish Food: Some people use zucchini, lettuce, banana, avocado, carrots, cucumbers, spinach, green beans, microwaved, raw or mushy - depending on what your fish like.
DIYer: A hobbyist who builds some parts of the aquarium and support parts themselves.
dKH: German degrees of Carbonate hardness.
DLC: Daleco, a MO business [see MO FAQ]
DLS: [see Double Layered Spiral]
DO: Dissolved Oxygen.
Dolomite: CaMg(CO3)2, sometimes used a substrate (and buffer) in SW tanks, but does not provide as good a buffer as crushed coral. [see Calciferous Materials]
DOC: Dissolved Organic Carbon. Ocean waters usually have 5-6 PPM.
DON: Dissolved Organic Nitrogen.
DOP: Dissolved Organic Phosphorus.
Dorsal: Refering to the top (or back) of the fish.
Dorsal Fin: The large fin mid-way down the top of the fish’s back.
Doser: A device most often used in reef tanks for automatically and constantly adding buffers, water additives or nutrients for inverts.
Dosing Pump: A type of Doser.
Double Layered Spiral: A biological filter media most often used in wet/dry filters. Seems to be going out of style because of better wet/dry biological filter media with more surface area and
more void space for better gas exchange.
Drift Wood: Wood that is OK to put in a fish tank. DIYers should clean and boil any found wood. Letting it soak in clean water before adding to tank may help to keep it from floating. Some fish
need the cellulose for proper nutrition. Note that tannins (tannic acid) leached from the wood (and
may color water), and slight decay may reduce pH to some degree and possibly soften the water.
Drilling Glass: Don’t try it, get a local company or store to do, preferably those who will guarantee if case of broken glass.
Drip Plate: Part of a wet/dry filter which allows water to drip through a plate with many small holes in it. [see Wet/Dry Filter]
Dropsy: An internal fish ailment in which the fish seems bloated and the scales stick out.
Drosophila: Fruit flies. Generally, in aquaria, deals with flightless varieties as fish food.
DTPA: Organic compounds used to chelate minerals.
Dupla: A German manufacturer of aquarium supplies which many consider to superior to all others. [C!]
“Dynamic Aquaria”: A book that is the center of a great deal of controversy, and promotes the idea of simulating the whole microsystem, and promotes algae scrubbers. [C!]

Echinoderms: Star fishes, sea urchins, among others.
EDTA: Organic compounds used to chelate cations with a +2 charge (i.e. calcium and magnesium).
Egg Depositors: Those egg laying fish which purposely deposit the eggs on a particular site, usually chosen for its desireable characteristics. They generally have more parental instincts than
egg scatterers.
Egg Layers: Those fish which do not have live births, and the eggs are fertilized and hatch external to the fish’s body. The eggs are usually placed in the substrate or on a suitable plant leaf
or rock. They are generally harder to raise then those having live births.
Egg Scatterers: Those egg laying fish which tend to disperse the eggs throughout an area.
Eggs: Usually refers to the eggs of Egg Layers, they are tiny, usually glossy in appearance.
Electrical Usage and Cost: Find electrical cost of a device, say a 100 w heater that is on approximately 50% of time throughout the year, will use 100 (watts) x 365 (days) x (24 hours) *
0.5 (time on) = 438000 watt-hours which is 438 kilo-watt-hours, and at $0.13 a kwHr, is about $57
a year. Each 15w bulb on for 12 hrs a day is 65.7 kwhrs and about $8.50 a year, although most
lamp ballasts aren’t completely efficient so its probably uses more than 15w. Make sure to take
into account air and water pumps, powerheads, all lights, any fans (like on light fixtures), chillers
and even timers (for lights).
Electronic Ballasts: Solid state devices for driving florescent bulbs, are generally cooler, more energy efficient and cause bulbs to last longer than standard ballasts. [see Ballasts]
Electronic Test Kits: A number of electronic devices exist for measuring water characteristics, most notably temperature, pH, and Redox. They are more accurate than chemical based tests
but are more expensive. Electronic pH testers are popular because they are relatively cheap and,
for many aquarists, will pay for themselves over time.
End Caps: The connectors in which florescent bulbs are fitted into. Most premade light fixtures have these included and are generally only needed in DIY projects.
Endpoint [pH]: When measuring Alkalinity by titration, it is the target pH level to which the pH of the test solution is lowered to. It is commonly 4.5 pH, but sometimes 4.9.
Enzyme: A substance that effects chemical reactions within an organism.
EPF: [see External Power Filter]
Erythromycin: A medication.
Established Tank: An aquarium that has completed its development of the nitrogen cycle and has supported fish successfully for at least a couple months, and is general stable.
Euthanasia: Don’t just flush ‘em, it seems that the best way is to put them in a small contained, with tank water and mostly ice, possibly even in the freezer. They go peacefully. Then dispose
of, in a sealed bag.
Evaporation: The process in which water molecules are dissolved into the atmosphere. This is especially prevalent in rooms with high temperature, low humidity, or a high capability for gas
exchange. Note that this also lowers temperature to some degree.
External Filter: Any filter outside of the tank. Usually a Power Filter of Canister Filter.
External Pump: A water pump that is not to be submersed in water. They generally run hot to the touch, are noisier, need to be primed and oiled, but do not contribute any heat to the water.

[F]: Symbol used in newsgroup subject lines to denote that the topic concerns freshwater setups.
F15: A designation on florescent lights of 15 watts.
F20: A designation on florescent lights of 20 watts.
F30: A designation on florescent lights of 30 watts.
F40: A designation on florescent lights of 40 watts.
F60: A designation on florescent lights of 60 watts.
Fxx: Other designation on florescent lights, often between 9 and 96 watts or more.
Fahrenheit: A measure of heat, subtract 32 and divide by 1.8 to find Celsius.
FAMA: Freshwater And Marine Aquarium, a magazine most often read by the "experts" but often hard to read and filled with ads.
Fancy Goldfish: Goldfish that have been literally inbreed to produce desirable mutations, such as double tails or bug eyes.
Farlowella spp.: An expensive, delicate fish that has been known to eat algae.
FAQ: Frequently Asked Questions, a document produced by members of a news group to help answer question and as an introduction. These FAQs are posted twice monthly to the USENET
news groups, are available at ftp.cco.caltech.edu/pub/aquaria/FAQfiles/Usenet/ in text form via
FTP or at in HTTP form at http://www.actwin.com/fish/faqhead.html. [see Also Reefkeepers’ FAQ]
Fauna: Animal.
FB: [see Fluidized Bed]
Fe: Chemical symbol for Iron.
Fe++: Chemical symbol for an iron ion.
Feeder Blocks: Commercially produced blocks of material that break down over time releasing food, supposedly for feeding while away from the tank. Generally considered a bad thing because
of material that breaks down, and food particles are usually too small and turn into waste. [see Feeding Fish] [C!]
Feeder Fish: Usually small common goldfish or (smaller) common guppies.
Feeding Fish: Be careful not to overfeed, they should be able to consume all the food in just a couple minutes. Make sure to clean up any uneaten food (unless bottom feeders will get it soon).
They are almost always hungry, but don’t need to be feed, of course there are exceptions to this,
so it’s best to consult a reference on the species you have. Most fish can go a few days or more
without being fed, or will nibble off algae and/or plants, although don’t test this if the size
difference of fish in the tank is substantial, or the big fish may snack on your small fish! [see BEGINNER FAQ]
Feeding Invertebrates: Usually done with a (new) turkey baster to place foods right by them or the food may often be eaten by another fish first.
Fertilizer: Usually in reference to plants, usually contains NPK, which, when combined with fish output, yields too much of this for the plants to utilize and caused algae growth.
Fibrous Peat: Peat that is composed of long strands or fibers or twigs. [see Peat]
Filter: Any device that cleans the water, either or both a Mechanical Filter or a Biological Filter or a Chemical Filter. [see BEGINNER FAQ]
Filter Bags: These are nylon bags used to hold any number of mechanical, biological or chemical filtration media. They come in a variety of sizes, are (generally) closed with a pull string, and
come in a variety of mesh sizes (to keep small particles in, out, or too allow larger water flows
through).
Filter Feeders: Those organisms who passively “strain” or “filter” the water as it passes by for tiny organisms on which they feed.
Filter Floss: A material of Dacron that resembles cotton balls that is used as a filter media. Polyester pillow stuffing can be used and is cheaper.
Filter Media: Almost any substance used to do either or some of Mechanical Filter and Biological Filter or Chemical Filter. Many sorts of media are available and all have their good and bad
points. [C!]
Filter Pads: Usually polyester or Dacron pads which serve as mechanical and biological filtration media, or sometimes in the form of pouches, which also serve to hold a chemical media, often
carbon.
Filter Plate: Usually refers to a plastic under gravel plate. [see Under gravel Filter]
Filtration System: The complete set of mechanical, biological, and chemical filters on a aquarium.
Fin Rot: Bacterial (or rarely viral or fungal) infection of a fish's fins that causes them to slowly disintegrate.
Fins: [see Adipose Fin, Caudal Fin, Dorsal Fin, Pectoral Fin, Pelvic, and Anal Fin]
FINS: Fish INformation Service. A collection of information mostly about marine fish, including pictures of many, information on some, and other general information which can be found at
http://www.actwin.com/fish/index.html.
Fish: If you’re looking this up, it may be time to consider a different hobby.
Fish Length: Measured from the tip of the head to the caudal penduncle (between the body and the tail fin).
Fish Loading: The rule of thumb on how many fish that can be added to an freshwater aquarium is not more than 1” of fish length [see Fish Length] per every gallon of water. This is only true for small, cigar shaped fish. Marine and cold water tanks support less, and reef tanks support much
less. Cold water tanks also support less. [see BEGINNER FAQ]
Fish Only Tanks: Dedicated to fish only, usually having conditions that would otherwise make it difficult for plants to flourish.
Fish Room: A room dedicated and designed for the preservation of the tanks inside it. [see FISH ROOM FAQ]
Fish Stress: Usually caused by bad water conditions, or by rapid changes in water conditions. Makes fish very susceptible to disease and infections.
FISHNET: A aquaria conference on CompuServe that one has to pay extra to have access to.
Fixture: What a light mounts into.
FKA: Fish Keeping Answers, a British magazine.
FL: Florescents Light.
Flake Food: The most common form of fish food.
Flame: A USENET post or electronic mail message which is abusive, usually in response to a misunderstanding, less often to heated topic or an ignorant statement. Can’t we all just get along!
Flat Worms: Planaira. Often occurring in aquaria in the presence of too much organic material (read: not clean enough) Are of little harm to fish.
Flexible Air Tubing: Often also used for water, usually 3/16 ID, 5/16 OD.
Float Switch: A water level controlled switch often used for adding make up water, or for shutting down pumps in case of a problem.
Floating Plants: Gives shade but may block enough light so that plants below don’t get enough, may also clog filter, especial surface skimmers, and may offer some protection to fry.
Floor Heating: [see Substrate Heating]
Floor Loading: Refers to maximum weight floors can withstand per sq. foot. Modern wood floors have a maximum load of 75 psf, which means any tank over 14” tall exceeds this rating.
Flora: Plant.
Floss: Polyester fluff used as mechanical and biological filtration media used most often in internal filters, and some canister and wet/dry filters.
Flow Rate: Measured in volume per time unit. Often in gallons or liters per hour. May often be stated in gallons or liters per day for water purifiers.
Fluidized Bed Filters: Is a sort of biological filtration mostly used on SW tanks, in which, water is pumped through a chamber containing very fine silica sand where bacteria has a very large
surface area for growth. It requires a prefilter or it will quickly become clogged, the output is also
very de-oxygenated and so this must be taken care of also.
Fluidized Sand: [see Fluidized Bed Filters]
Flukes: Small parasites which afflict fish and often cause lumps on/under scales.
Flying Fox: A fish that does not eat algae, often confused with SAE.
FOAF: Friend Of A Friend.
Foam: A biological and mechanical filter media. [see Sponge Filter]
Foam Filters: [see Sponge Filter]
Foam Fractionation: [see Protein Skimmer]
Foot Candles: A measure of light, equal to 1 lumen over 1 sq. ft.
Formaldehyde: Sometimes used as a medication.
FPT: Female Pipe Thread, for plumbing supplies.
Freshwater: An aquarium using water with no salt, although sometimes very small amounts are used.
Free Ammonia: Refers to the presence of toxic ammonia as compared to ammonia as ammonium (less toxic).
Freeze Dried Food: A food packaging process in which the food is frozen very quickly and then packaged under a vacuum to preserve freshness. They should be reconstituted in some tank
water first before being used as food.
Frozen Food: [see Freeze Dried Food]
Fry: Recently hatched fish. They need special care. [see Raising Fish]
FS: For Sale.
ft.: Feet or foot.
FTP: File Transfer Protocol, a method of retrieving files from another computer across the internet.
FTP, How to: Send mail to Jeff Pfohl for a detailed guide.
Full Spectrum Light: Attempt to duplicate the spectrum of light given off by the sun.
Fungus: A fish affliction where cottony fluffy or thread like growths from on the body of the fish, often around other wounds.
FW: [see Fresh Water]
FWIW (or FWIW1): (1) “For What It's Worth, vol. 1”, a publication from FAMA for DIYers.(2) For What Its Worth, meaning here’s my observation or experience, but it isn’t the end-all
answer.
FYI: For Your Information.

g: Gram or Gallon
[G]: Symbol used in newsgroup subject lines to denote that the topic is of general concern.
GAC: [see Granulated Activated Carbon]
gal: Gallon, multiply by 4.228 to get liters.
Gametes: An egg or sperm.
Gammerus: Baby FW shrimp, used in fish foods.
Gang Value: A device used to regulate one incoming air line into many outgoing air lines.
Gas Bubble Disease: A fish affliction usually caused by water super saturated with O2 (this being caused by malfunctioning pumps or powerheads, or cold tap water being heated). [C!]
Gas Exchange: This is an important part of any aquarium, especially SW tanks, where a high surface area of water is exposed to air, resulting in reoxygenating the water, and off gassing
unwanted gasses. Note that systems with exceptional gas exchange capabilities often are prone
to high evaporation.
Gas Reactors: [see Reactors]
German Peat: [see Fibrous Peat]
Gestation: The incubation (pregnancy) period of live bearers
GFI: [see Ground Fault Interrupts]
GH: [see General Hardness]
Gills: The internal organs (although exposed from the outside) used for respiration.
Glass: What most aquarium are built of. Compared to acrylic, they are more easily cracked, or shattered, heavier, but cheaper.
Glassworms: Larvae of Chaoboius, used as live and freeze-dried food.
gm: Gram. [see Metric System]
Goldfish: This species, despite popular use, are not tropical community fish. They are cold water fish and will not thrive well in a tropical community tank.
Grains: Divide by 480 to find ounces. [see GPG]
Granulated Activated Carbon: A chemical filter media that removes many kinds of chemicals by adsorption and absorption, mostly organics, dust, lead, and gasses from the fish tank, usually
"bad" chemicals, but often useful micronutrients. Does need to be replaced periodically, if left too
long, can leach chemical back into tank, possibly in a worse form. There is some controversey
over how much and how often to replaced. Some carbon may actually leach phosphorus and this
should be avoided in reef tanks, SW tanks, and/or any tank with an algae problem. Will also
remove most medications. [C!]
Granulated Charcoal: [see Granulated Activated Carbon]
Granulated Carbon: [see Granulated Activated Carbon]
Gravel: The most common substrate. Available in almost any size or variety of sizes from sand to small pebbles. Depending on the composition of the gravel, may have many natural colors.
May also come “painted” in many unnatural colors, this is not recommended, especially for plants
and UGF. Before adding new gravel to your tank make sure to rinse it thoroughly.
Gravel Vacuum: Usually a siphon driven device which removes particles and detritus from the gravel, usually to a bucket which is disposed of, and the water replaced by new water. This is
essential for tanks with UGFs or in reef tanks where cleanliness is important.
Gravel Washer: [see Gravel Vacuum]
Grease Algae: [see Cyanobacteria]
Green Water: [see Algae Bloom]
Grindal Worms: Similar to white worms, to about 1/2” in size.
Ground Fault Interrupts: A device designed to cut electrical power in case of a short.
Grounding: Are devices used in or near a the aquarium should be properly grounded, including being plugged into a GFI for the protection of the aquarium dwellers and the keeper.
Grounding Probe: A special metal probe placed in the tank and connected to an electrical outlet ground. Supposedly, this reduces any stray electrical currents (from pump motors, heaters and
florescent lights), but some feel this may actually worsen the situation. Usually made of the few
metals that are SW safe, platinum or Stainless steel (grade SS 316). [C!]
gpd: Gallons Per Day, often used in expressing output of DO or DI filters.
GPG: Grains Per Gallon, a US measure of concentration, multiply by 17.11854 for PPM
GPH: Gallons Per Hour, multiply by 3.8 to find LPH.
GPM: Gallons Per Minute.

H: Chemical Symbol for Hydrogen atom.
H+: Chemical symbol for hydrogen ion. [see pH]
H2CO3: Chemical symbol for carbonic acid, a result of CO2 dissolved in water.
H20: Chemical symbol for water.
H2S: Chemical symbol for Hydrogen Sulfide.
H2PO4-: Chemical symbol for a form of phosphorus.
Hach: Makers of test kits, very well recommended.
Hair Algae: Long green strands in SW tanks. Can be avoided by keeping tank dark while cycling, keeping nitrates and phosphates low, and keep tank free of detritus. Some herbivores and snails
will eat it before it gets too long, or remove by hand.
Halimeda: A calcareous macroalgea in SW tanks, it seems to be OK. [C!]
Halogen Lights: A type of light that because of its yellow dominated spectral output is not recommended for aquaria.
Hard Corals: Corals which develop an external calcareous skeleton. They are often more difficult to keep than soft corals and require more perfect water quality.
Hard Water: Water with a high degree of hardness.
Hardness: Commonly a measure of the molar concentration of dissolved CaCO3 in water. There are a number of different scales, a common one is DH.
0 to 4 DH very soft
5 to 8 DH soft
9 to 12 DH medium hard
13 to 20 DH hard
over 20 DH not used in fish keeping
Hatchery: May refer to either a tank [see Breeder Tank] or to a small plastic container walled by fine netting that is place inside a tank to separate the mother from the rest of the tank. The
bottom of such a device usually has some sort of contraption to isolate the fry or eggs.
Hazy Water: [see Cloudy Water]
Head: [see Pump Head]
Heater: A device which keeps the warms the water to a steady temperature, the rule of thumb is 2 watts per gallon of water in a normally heated room, 3w/gal in rooms that get cold in the winter,
or 4 watts or more per gallon in unheated rooms. For large tanks, tanks (and filters) with large
surface areas, cold rooms, or redundancy, get two or more heaters that add up to the required
wattage; its better to overestimate. It’s better to keep any one heater at 2 to 3 w/gal and use
multiple heaters to get more watts per gallon because in case of one heater being “stuck on” it will
not heat the tank water to toxic levels as quickly (resulting in boiled fish). Never run while out of
water, and never place in water if hot.
Heating Coils: Usually used in plant tanks, but also useful in fish only tanks, they are a power supply and a length of heating element that is placed atop a thin layer of substrate and then
covered with a thicker layer of substrate. For all tanks this provides small currents in the
substrate to provide fresh oxygenated water to bacteria, considered better than UGFs at avoiding
anaerobic areas. For plant tanks it also has the benefit of keeping the roots warm which is
important.
Herbivore: Primarily eats plants or foods derived from plants.
Hermaphrodite: Having or playing the part of both sexes.
Hermatypic: Stony corals with Zooxanthellae. They have higher calcification rates.
Herpetology: The interest in reptiles, turtles, and snakes.
Heterotrophic Bacteria: Bacteria which produce energy by taking in and metabolizing organic compounds (i.e. sugars), and which use these compounds as carbon sources. Compare with
autotrophic bacteria.
Hex: Meaning six, in fish keeping usually refers to hexagonal (6 sided) tanks.
HCO3-: Chemical symbol for Bicarbonate.
HO: High Output, refers to lighting. 800 mA. They generally about 1.5 to 2 times as much wattage as same length NO bulbs. Although it has suggested they are not as efficient as (per
watt), and tend to have a shorted life span than SO bulbs.
Hood: The top of the tank, used to mount lights on, and keep fish and moisture in.
Hospital Tank: A tank set up similar to a breeder tank, except that it is used for isolating and treating fish ills. It can be as simple as a 10 gallon, dimly lite (ill fish don’t like light), a sponge filter
(which should be cycled in an existing tank), an airstone, a heater and thermometer, and perhaps
a piece of artificial rock/plant as a hiding place. Note that carbon will remove most medications so
don’t use it in any medicated tank.
HP: Horse Power, a US measurement of power, usually used in reference to chillers.
HPO4--: Chemical symbol for a form of phosphorus.
HPS: High Pressure Sodium. A type of lighting *NOT* suitable for aquaria because of its poor spectral output.
HTML: Hyper Text Mark-up Language, a scripting language for creating pages for the Web.
HTTP: Hyper Text Transport Protocol, an address which denotes a Web resource.
Humans: For all the reading fish out there, this is us, the organisms that attempt to keep you in small square tanks.
Hydrogen: Chemical symbol H. Very abundant.
Hydrogen Sulfide: Chemical symbol H2S. A toxic gas (smells like rotten eggs) created by the reduction of sulfates by anaerobic bacteria. It’s usually produced in misadjusted denitrators, or in
other stagnant biological filtration.
Hydrometer: A device for measuring the specific gravity of water, must be adjusted for water temperature. [see REEFKEEPERS FAQ]
Hydrophilic: A substance with a chemical or molecular attraction for water. Often used in discussions of protein skimmers.
Hydrophobic: A substance with chemical or molecular opposition for water. Often used in discussions of protein skimmers.

I: Chemical symbol for Iodine.
Ichthyology: The study of fishies!
Ick: AKA freshwater white spot disease.
ID: Internal diameter of a tube or pipe.
IMHO: In My Humble Opinion
IMO: In My Opinion
Impeller: The propeller shaped device in pumps which moves water.
Imperial Measurements: [see UK Measurements]
in.: Inches
Incandescence: A common type of light bulb in which light is produced by a heated filament (like used in house lamps, etc.) that is sometimes used in small tanks or for special cases. Generally,
it produces the wrong spectrum (about 3000 K, mostly red), too much heat, and is inefficient.
Infusoria: A collection of tiny organisms such as algae, plants and animals that is often used as food for fry and filter feeders.
Initial Lumens: When referring to lamp output, this is after a burn-in period of about 100 hrs.
Inorganic: Not a carbon containing compound, except for CO2, the bicarbonate ion (and salts of this ion), and carbon disulfide which are also considered to be inorganic.
Internal Filter: Any filter which resides in the tank, usually a bubble filter, but some power filters and canister filters are internal.
Inverts: [see Invertebrates]
Invertebrates: An animal with no spine or backbone, most often found in SW tanks, but some others exist such as FW shrimp. Inverts usually require iodine, cobalt, vanadium and arsenic,
among other elements.
Iodide: A form of Iodine.
Iodine: Chemical symbol I. Useful in reef tanks for soft corals molting crustaceans. Removed by Protein Skimming. Too much may result in red slime algae (Cyanobacteria) or poisoning of fish
and inverts. At levels about 0.05 PPM in natural sea water.
Ion: An atom or molecule that has either a negative or positive charge. In mail and posts it often takes the following forms, although in print the signs are often subscripted (in the case of an Iron
ion): Fe+ Fe- Fe++ Fe-2. Note that -- and -2 are the same but only written differently.
Ion Exchange Resins: A class of chemicals, many of which have some sort of chemical filtration property by absorbing specific ions (and releasing others) such as ammonia, nitrate, metals, etc.
[see FILTER FAQ]
Iron: Chemical symbol Fe. A micronutrient, often lacking for plants, but only useful when in its doubly oxidized state Fe++.

Jaubert: A person of the Monaco public aquariums who has initiated interest in live sand and is well known for other aquaria research.
Jumping Fish Control: Make sure your tank is well covered, or, for uncovered tanks, has a barrier
along the walls of the tank that extend a few inches up.
Juveniles: Fish or other organisms which have past the just-born stage, but have yet to fully mature.

K: [see Kelvin]
K+: Chemical Symbol for Potassium, sometimes written without the plus sign.
K2O: Chemical symbol for Potash.
Kalkwasser: (“chalk-water”) Saturated Ca(OH)2 Solution, used in reef tanks for maintaining calcium levels. It should be added very slowly to reduce the possibility of buffering capacity
reduction. [see REEF FAQ]
Kelvin: (1) A measurement of heat, subtract 273 to find centigrade.(2) Often used to represent spectral output of lamps. [see Color Temperature]
KH: Carbonate Hardness, the K coming from the original German spelling of carbonate, a measure of alkalinity.
Killifishes: FW egg-laying fish. [see newsgroup alt.aquaria.killies]
Killing Fish: [see Euthanasia]
Koi: A carp, a relative of goldfish, typically found in ponds. Various strains are breed, and often placed in competition, and are very highly valued.
Koi USA: A magazine.
KRIB, The: A WWW page at http://marge.phys.washington.edu/fish/index.html by Erik Olson that has plenty of information on fish, and links to other sites.
Kribs: [see Kribensis]
Kribensis: Common name for Pelvicachromis pulcher, a west-African riverine Cichlid.
Krill: Euphausia sp., A frozen or frieze dried food, especially for larger fish.

[L]: Symbol used in newsgroup subject lines to denote long messages.
Labyrinth fish: Sub-order Anabantoidei. A group of fishes who can take oxygen straight from atmosphere. Most are found from Asia. Includes such common aquarium fish as Bettas, Gouramis
and Paradise Fish.
LaMotte: Makers of test kits which many consider the best and most reliable.
Larvae: The pre-adult stage in the life cycle of some organisms. For example, the larval stage of a butterfly is a caterpillar, and of a frog is a tadpole. In aquaria, many parasites have such
lifecycles. Most marine fish go through a larval stage when they first hatch - this is partly why they
are so difficult to breed in captivity.
Lateral Line: Many fish has a special sensing organ along their lateral line down their body which allows them to sense vibration.
Lateral Line Syndrome: A affliction that occurs in Marine fish in which they start losing scales and skin along the lateral line along the body. Possible reasons include too high nitrate levels, vitamin
deficiencies, poor limited spectrum lighting or stray voltages, or too much carbon filtration in the
tank. [C!]
Laterite: A substrate composed of clay containing iron. Often used as a sub-layer of the substrate for promoting good plant growth.
Lava Rock: Usually safe for aquariums but may contain iron which may be better for FW plant tanks, and not so good for SW tanks (helps algae). [see Rocks]
lb.: Pounds
Lead: An element that may be found in tap water. It is of unknown toxicity to fish and other aquatic life. [C!]
Lift Tubes: Usually 1" diameter stiff clear plastic tubes that are used with UGF.
Light Cycle: Most plants will do best in 10-14 hours of light per day, any more is likely to lead to unwanted algae growth. [see PLANT FAQ]
Light Duration: [see Light Cycle]
Light Intensity: Depends on light distance from top of tank, surface area and depth of tank. Rules of thumb are 3 to 4 watts/gal. for reefs (of 50/50s), and 2 watts/gal for fresh water. Note that taller
tanks need more light and that the intensity of light diminishes as the water gets deeper.
Insufficient light intensity results in thin, weak, yellow leaves and stems on plants, they may also
angle dramatically towards light source. In reef tanks, proper light intensity is a necessity because
many of the organisms are photosynthetic. Tropical waters get about 10,000 lumens per sq. ft.
[see PLANT FAQ]
Light Spectrum: The spectrum of the light coming into your tank means as much or more than the intensity of the light. Incorrect spectrum in a FW tank will result in algae outbreaks, dead plants
and unhappy fish, or in a marine tank will generally result in loss of invertebrate life. The
chlorophyll in plants utilize the red and blue spectrums, red spectrum yields tall growth, while blue
yields study, full plants, but should have a equal amount of each.
Light Timer: A inexpensive device that turns on and off lights on a regular daily schedule, generally considered a good idea.
Lighting: Most bulbs need to be replaced every 6 months to a year because of reduced light output, or shifts in color spectrum. Some bulbs will last longer, some shorter. Output and
spectrum decay are generally not linear throughout the life of the bulb. [see Lighting FAQ]
Lime: A name commonly given to mineral encrustings around tanks tops, inside of tanks, and on hardware caused by the evaporation of hard water.
Lime Reactor: A device for adding calcium to a reef tank by bubbling CO2 over a calcerous substance which dissolves.
Lime Remover: Any number of chemicals used to dissolve and remove lime deposits. It has been suggested that pure strong vinegar will remove it when flushed with water and scrubbing
(using non-abrasive material).
Limescale: [see Lime]
Limestone: Check for its presence using the Vinegar Test.
Limewater: [see Kalkwasser]
Limewood: A wood that some air stones are made of, especially those used in protein skimmer because they produce exceptionally fine bubbles, but create a large back pressure on the air
pump, so this limits the amount of air pushed through the wood.
Liner: A plastic/rubber sheet used to create ponds.
Liter: A metric measurement for capacity.
Live Bearers: Fish or other organisms which give birth to live young, as compared to egg layers. They are generally easier to raise than those of egg layers. Note that many species will eat their
own young, and many times removing the parent(s) is the best idea.
Live Food: A food source for fish, and other aquarium animals that has benefits over flake food. A certain species may have a affinity for certain live foods, others will eat just about anything. A
variety of live foods in addition to flake foods make for a better diet for your pets.
Live Rock: Used especially in reefs, and marine tanks only, very porous, covered with Coralline algae and small living creatures. For Berlin style tanks, about 2.5 lbs per gallon of rock are used,
but basically the target is to fill half the volume of the tank with LR. Its many organisms form a
biological filtration, and includes denitrifying bacteria deep inside in near anaerobic conditions.
[see LIVE ROCK FAQ ]
Live Sand: A substrate consisting of very small pieces of crushed coral and shells used in SW tanks, especially reef tanks, that has an assortment of bacteria, micro algae, and crustaceans that
helps biologically filter the water and supposedly reduces nitrates. It requires fish that with “turn-
over” or stir up the substrate. [C!]
Loading: [see Floor Loading] or [see Fish Loading]
[Long]: Symbol used in newsgroup subject lines to denote long messages.
LPH: Liters Per Hour, divide by 3.8 to find GPH.
LR: Live Rock. [see Live Rock]
Lurking: One who reads a USENET news group but does not post, will sometimes send private EMail in response to a post, usually after some time. One is considered to “de-lurk” after posting
first message.
Lumens: A measure of the intensity of light. Multiply by 10.76 to find Lux.
Lux: An ISO measure of the intensity of light. Divide by 10.76 to find Lumens.

[M]: Symbol used in newsgroup subject lines to denote that the topic concerns marine setups.
mA: milli Amps, or 1/1000th of an Amp.
Mg: Chemical symbol for Magnesium.
Mg++: Chemical symbol for a Magnesium ion.
MACNA: Marine Aquarium Conference of North America.
Macro Algae: Complex multi-celled algae in SW tanks having a structure called a Thallus.
Make Up Water: Water that is added to makes to make up for water lost due to evaporation.
Magnesium: Chemical symbol Mg. An element that is a trace element for plants. Deficiencies show themselves as yellow leaves but with green veins, as it is a component of chlorophyll.
Magnetic Impeller: A part of many power filters in which the propeller is driven by magnetic fields from the other side a water tight area.
Mail Order: Basically, if you order from MOPS, TFP or PW you’re probably going to be happy.
Every MO place has its ups and downs, its supporters and its detractors. IMPORTANT: One thing is certain, you’re going to pay a significantly lower price MO than at local shops, but at the
cost of not getting knowledgeable help and support from the MO place. If you require this sort of
help, don’t expect your local store to provide it to you free while you buy MO, this is not fair. Other
places (than the ones listed above) probably are smaller, or have less respect by the aquaria
community, of course be aware of possibility of scams. [see MO FAQ]
Mailing Lists: Mailing lists are internet constructs in which electronic mail is automatically forwarded to the many recipients of the list, as are replies, so everyone can see the
correspondence. Generally, have been replaced by USENET, because of efficiency, but some
still flourish and many result in a substantial mail. Refer to the following table and the subscription
instructions below.
List Name Listserv Address
======== =============
AQUARIUM LISTSERV@enuvm1.cc.emory.edu
BETTAS LISTSERV@LISTSERV.ARIZONA.EDU
Cichlids mail-server@mailmill.com
discus-l listserv@cornell.edu
AQUA-L LISTSERV@VM.UOGUELPH.CA (Aquaculture)
There are many others not directly related to home aquaria but may be of interest anyway, and a
list of them can be found at http://www.actwin.com/fish/lists.html.
Send mail to the listserv address of the mailing list to which you want to subscribe, and in the
body of the message include the words “SUBSCRIBE” the List Name and Your Name on the
same line, in that order. You should get a receipt back some time soon. Make sure to read
response on how to properly post to list, or to post to list manager (in case of problems)
Malachite green: A medication.
Malawi: A lake from which some species of Cichlids come from.
Malaysian Trumpet (or Burrowing) Snails: A freshwater snail that has a cone shaped shell, is not known to eat plants, may help keep algae in check and will burrow through “turn over” the
substrate.
Manganese: Chemical symbol Mn. A metallic element that is a trace element for plants. Deficiencies show themselves as yellow leaves but with green veins.
Mantle: Exposed part of some clams when shells halfs are open.
Maracin: An antibiotic, also useful on blue green algae.
Marbles: Sometimes used as a substrate in aquariums, especially freshwater, but not to be used with UGF. Larger sizes seen in egg laying breeder tanks so eggs drop in cracks so as avoid
being eaten by parents.
Marine: An aquarium that mimics the ocean in that it has salt in the water and other special characteristics.
Marshall Rock: Premium LR from the Marshall Islands which tends to be less dense than Florida rock. [see Live Rock]
Matrix: Grid of PVC through which water is pumped in some reef setups to improve circulation.
Matrix Manifold: [see Matrix]
Mealworm: A live or freeze-dried larvae of the flour beetle.
Measurements: [see Metric System] [see US Measurements]
Mechanical Filter: Any filter which removes small particles from the water by trapping them.
Mechanical Filter Media: Any porous material from sponges to floss to diatoms which is good at trapping small particles.
Media: [see Filter Media]
Medications: [see Chemicals for more information this and other substances]
Medium BiPin: The pin layout on most florescent tubes used in aquaria. Also known as G13 (ANSI) and G5.3 (IEC).
Mercury Vapor Lights: Provide a lot of light and are especially good for tanks over 16 inches deep, but do not produce as much or as good lighting as MH, but are cheaper.
Mesenterial Filaments: A part of corals used both in digestion and as as offensive structure.
Metal Halide Lights: More expensive, brighter, and better light but run hotter than standard florescence, and they also require special ballasts and fixtures. They have very sun-like spectral
output. Some find they last longer than comparably bright VHO bulbs. Most will require a UV
shield.
Methanol Denitrator: A device that supplies bacteria with Methanol as food so as to increase their processing of nitrate. They may take the form of a coil of tubing or a holding tank.
Methyl Blue: An organic dye, used as a biological stain. Also has anti-septic qualities.
Metric System: Measures of Length
m meter 39.37 inches 3.28 feet
cm centimeter 0.01 m 0.39 inches
mm millimeter 0.001 m 0.039 inches
Measures of Area
m^2 square meters 1550 square inches 10.76 square feet
cm^2 square centimeter 0.155 square inches
Measure of Volume
l liter 0.26 gals 61.02 cubic inches 0.0353 cubic feet
ml milliliter 0.001 liters 0.0061 cubic in. 20 large drops
cm^3 1 ml
m^3 cubic meter 35.28 cubic feet
Measure of Mass
kg killogram 1000 grams 35 ounces 2.2 lb.
g gram 0.035 ounce
mg milligram 0.001 grams 0.015 grains
mEq: In most cases, basically equivalent to a millimolar, which is 1/1000th of a mole of a compound per liter of solution.
mEq/l: Milli Equivalents per liter, another scale of hardness, multiply by 50 to find PPM of CaCO3, or by 2.8 to find dGH.
MFM: Marine Fish Monthly, a magazine.
mg: Milligram, a metric measure of mass. [see Metric System]
MH: [see Metal Halide lights]
Micro Algae: Single celled algae.
Micro Reef: A small sized mini-reef, perhaps any reef below 30 gallons down to even 5 gallon tanks. Micro reefs generally require more maintenance and monitoring for them to be successful.
Micron: A measure of length equal to 1/1000 of a millimeter, same as a micrometer.
Micron Filter: A mechanical filter which has the capability to trap extremely small particles, and even small bacteria. Similar in function to diatom filters.
Micronutrients: Small amounts of trace elements and chemicals needed for organisms. Usually used in discussion of reefs, plants, Cichlids and goldfish.
Mil: A unit of measure equal to 1/1000th of an inch, or about 0.0254 mm.
Milt: Sperm.
Mineralization: The process in which heterotrophic bacteria break down organic wastes into inorganic nitrogen. [see Nitrogen Cycle]
Mini Reef: An indoor, kept reef aquarium.
Miniscus: Because of the “stickiness” of water, it tends to creep slightly up the sides of its container. In a small diameter container, such as a test tube, this rounded surface is the
miniscus.
Mixed Bed Resin: A chemical filtration media used in DI filters.
mm: Millimeter, a metric measure of length. [see Metric System]
mM: Milli-Molar, or 1/1000th molar.
Mn: Chemical symbol for Manganese.
MO or M/O: [see Mail Order]
Moe, Martin: An author of aquarium books, especially noted for “Marine Aquarium Handbook” a must for any beginner SW keeper.
Mole: A scientific term for the amount of compound in one gram molecular weight. Example: since water has a molecular weight of 18, one mole of water is 18grams.
Mollusk: An animal with a hard shell such as clams, mussels.
Molting: The shedding of external skin, or shell, often occurs in crustaceans.
Molybdenum: A trace element in Reef tanks used by hard corals. Levels of about 10 ppb in natural sea water.
Monofilament Line: AKA fishing line. Often used in reef tanks to tie rocks or similar objects together. Could also be used in fish only SW, or FW for similar applications.
Moon Cycle: A light cycle that it supposed to simulate the light from the moon, especially in reef tanks where it is felt that this helps invertebrate spawning.
Moonlight Bulb: A usually incandescent low wattage bulb used during moon cycles.
MOP[S]: Mail Order Pet Shop, a MO business. [see MO FAQ]
Mouthbrooding: An unusual practice in which the fish eggs are externally fertilized and incubated within the mouth/throat of one of the parents.
Moving a Tank: Refer to the FAQ. Be very careful. Don’t attempt to move a tank filled with water, it will surely break. Always lift tank from bottom, its best if tank is on a rigid board and just
move the board with tank on it.
MPT: Male Pipe Thread, for plumbing supplies.
Mystery Snail: A snail known not to frequently feed on plants.
mV: Millivolt, 1/1000 of a volt.
Mulm: Waste that has been detoxified.

N: Chemical symbol for Nitrogen.
N2: Chemical symbol for Dinitrogen.
N20: Chemical symbol for Nitrous Oxide.
N-NH3: Chemical symbol for nitrogen ammonia ion.
N-NO2--: Chemical symbol for nitrogen nitrite ion.
N-NO3-: Chemical symbol for nitrogen nitrate ion.
Na: Chemical symbol for Sodium.
NaCl: Chemical symbol for Sodium Chloride. Common table salt.
NaHCO3: Chemical symbol for sodium bicarbonate.
Naupalii: The very young form of any number of creatures, often Brine shrimp, used as very fine food.
Nessler: A type of test for ammonia. Not appropriate for SW tanks. Tests false-positive for many deaminators. Compare to Salicyate.
Nematocysts: Stinging cells of some anemones.
Net.Authors: People who frequent the newsgroups and have had something published on the outside (real world).
Net.Curse: [see Pl*co]
Neutral Light: Light which has a spectral output of about 3500 Kelvin.
New Tank Syndrome: During initial cycling, ammonia and nitrite levels may reach levels far above toxicity for fish, causes death and illness. This can be avoided by often small water changes to
check toxin levels under control but allow enough of them to feed the growing bacteria bed. This
effect is usually amplified by overeager keepers who add fish too soon, too fast, or too often. As a
rule of thumb, not more than 1” of (hardy) fish per 10 gallons for the first 4 to 6 weeks, or until the
nitrites have returned to zero. Do not remove biological filter media (i.e. power filter media) during
this time.
Newbie: A person new (and usually ignorant) to either fish keeping and/or network protocol.
Newsgroups: alt.aquaria, rec.aquaria, sci.aquaria on USENET News.
Neutral: Having a pH of 7.0.
NFS: Not For Sale. Often seen in aquarium stores on the tanks.
Nitrate: [see Nitrate Ion]
Nitrate Factory: A phrase used to describe any biological filtration that is a very efficient of Nitrates, which are very bad in SW and especially Reef tanks with invertebrates. UGF’s and
Trickle Filters are usually the target of this term.
Nitrate Ion: Chemical symbol NO3-, fairly toxic to aquarium organisms, part of the nitrogen cycle.
Freshwater and saltwater fish stress above 60 PPM, plants may die before that level. 10-15 PPM
is acceptable, although below 5 will reduce algae growth. For reef tanks, nitrate should not
exceed 5 PPM, below 1 is acceptable, and near 0 is optimal. May be present in tap water.
Excess nitrate will cause decay of plant leaves that looks like small holes that get larger with time.
Nitrification: The conversion of ammonia to nitrite and nitrate by nitrifying bacteria. [see Nitrogen Cycle]
Nitrite: [see Nitrite Ion]
Nitrite Ion: Chemical symbol NO2-, toxic to aquarium organisms, part of the nitrogen cycle. Should not go above a couple PPM, and 0 is optimal.
Nitrobacter Bacteria: Part of the nitrogen cycle which converts nitrite to nitrate. [see Nitrogen Cycle]
Nitrogen: Chemical symbol N.
Nitrogen Cycle: The biological cycle in which bacteria break down biological waste (organics) into ammonia (or ammonium), to nitrites, to nitrates and then finally to nitrogen (all inorganic). Plants
use inorganic forms of nitrogen with the exception (mostly) of gaseous N, and convert them in
organic forms, which, presumable, are eaten by fish, and eventually end up again as fish waste
and the cycle repeats. [see H20 FAQ]
Nitrogen Fixation: Conversion of atmospheric nitrogen into nitrate by some plants and bacteria (Cyanobacteria for one).
Nitrogen-Ion: The nitrogen-ion chemicals symbols are written prefixed by an “N-”. Example: N-NH3, the nitrogen ion symbol for ammonia.
Nitrosomonas Bacteria: Part of the nitrogen cycle which converts ammonia and ammonium to nitrite. [see Nitrogen Cycle]
NH3: Chemical symbol for ammonia. [see Ammonia]
NH4+: Chemical symbol for ammonium ion [see Ammonium Ion] , sometimes written without plus sign.
nm: Nanometers, commonly measure of wavelength of light.
NO: Normal Output, as compared to HO and VHO, used when describing florescent bulbs. 425 mA.
NO2-: Chemical symbol for nitrite ion [see Nitrite Ion] , sometimes written without negative sign.
NO3-: Chemical symbol for nitrate ion. [see Nitrate Ion]
Nocturnal: Relating to or occurring during the night (dark cycle), often relating to the activity or eating patterns of aquatic life.
Node: Usually refers to a plant node, which is the point along the stem at which either another stem or leaf comes off from.
NovAqua: A popular chemical with the properties of AmQuel, plus detoxifies heavy metals. [see Water Conditions]
NPK: Nitrogen, phosphate, potassium. The three primary nutrients of plants, normally supplied by fish.
Nuchal Hump: An extended, protruding “forehead” on some muture male Cichlids.
Nudibrachs: Marine sea slugs.
Nutrient Poor: The conditions under which corals develop the best, otherwise, they are unable to outcompete algae.
Nutrients: The simple and complex chemicals a living thing needs to flourish, usually in small amounts of many substances. They usually fall into the following catagories, inorganic nitrogen,
phosphorus, and carbon.
Nursery Tank: [see Breeder Tank]

O: Chemical symbol for the Oxygen atom.
O2: Chemical symbol for the Oxygen molecule.
O3: Chemical symbol for ozone. [see Ozone]
OD: Outside diameter of a tube or pipe.
Off Gas: Expel. Often to let some chemicals such as ammonia, chlorine or CO2 to escape into the air from the water if water is aerated.
Omnivore: Will eat both plants and animals, or food derived from plants or animals.
"Optimum Aquarium": A book that is the center of a great deal of controversy.[C!]
Operculum: The area covering the gill openings.
Organic: Composed of materials from plants or animals.
ORP: Oxidation Reduction Potential. [see Redox]
Orthophosphate: A form of inorganic phosphate.
Otocinclus sp.: A family of algae eaters. Doesn’t seem to harm plants. Have a high oxygen content so make sure your tank is sufficiently aereted.
OTOH: On The Other Hand.
Otos: [see Otocinclus sp.]
Overflow Box: A box that hangs on the outside of the tank which feeds water to a wet/dry or a sump, often is designed to keep water level.
Overflow Tube: A bent tube that siphons water out of the tank into an overflow box. It often contains an air check valve (mounted on its highest point) to easily remove trapped air that builds
up.
Overflow Pipe: [see Overflow Tube]
Oviparous: Egg laying.
Oxidation: [see Oxidizing]
Oxidizing: The chemical process in which an oxidizing agent reacts with another chemical, taking the other chemical’s electrons.
Oxygen: Chemical symbol O2. Required by all fish and plants (during dark cycle) and many sorts of beneficial bacteria. Produced by plants during light cycles. Generally the water should be
saturated with O2 for best aquarium environment. Saturation levels decrease with added salts,
and temperature. At 80F, fresh water saturates at about 8 PPM, and sea water at about 6.5 PPM.
Oxygen Diffuser: A device (such as an airstone) or a chamber used to allow O2 to dissolve in solution.
Ozone: Chemical symbol O3, a highly unstable form of oxygen. It very easily gives up the third O atom and single oxygen atoms are very reactive and will oxidize almost any other molecule it can
find, usually organics.
Ozone Filters: A filter that uses ozone to remove organics from the water and kill bacteria and small organisms, most often used in reef but sometimes in marine aquariums. Is also toxic to
aquarium organisms so care must be taken not to allow back into the aquarium before being
filtered out by carbon. It is very dangerous in this way and care must be taken, it is also
dangerous to humans. Although it often used in larger installations, it’s use for most aquarists is
for infrequent use to improve water quality or to control parasites or unwanted bacteria. Some
have suggested that long term use can be detrimental. UV filters are preferred. It is created most
commonly by an alternating electric spark, or by a UV light of 195 nm.
Ozone Safe: Because of the reactive nature of Ozone, all materials that come in contact with it must be Ozone Safe. Amoung other things, ozone rapidly breaks down rubber.
Ozonizers: [se Ozone Filters]

[P]: Symbol used in newsgroup subject lines to denote that the topic concerns reef plants.
P: Chemical symbol for Phosphorus atom.
Painted Glass Fish: Yes, they are painted. Yes, it will fade. Yes, it is cruel. You should *not* buy
them.
Parasite: An organism that lives off another usually to the others misfortune. Most are
communicatable to other hosts.
Peat: An organic material consisting of small particles of composted forest fibers used to soften
water and make it more acidic. [see FILTER FAQ]
Pectoral Fins: The pair of fins just behind the fishes head.
Pelagic: Dealing with or occuring in the water, as compared to benthic, or occuring at the surface.
Pelvic Fins: The pair of fins located low on the sides of the fish, just in front of the anal fin.
Pendant [Spot] Lights: Suspended dome shaped light fixtures that most often hold MH bulbs.
Periastolic Pump: A Doser which operates by squeezing tubing. [see Doser]
Periodic Water Changes: It is good to change 25% of the water every three weeks, but make
sure you de-chloraminate the water. This rate may be adjusted up or down depending on the
species and amount of fish loading. [see BEGINNER FAQ]
PF: Practical Fishkeeping, a British magazine, good but has been compared to "USA Today" and
"People".
PFK: [see PF]
pH: “Power of Hydrogen” A measure of free H+ ions, or the basicness or acidity of the water. [see
WATER FAQ] More specifically, the negative logarithm of hydrogen anion concentration, in
molarity. Note, because it is a logarithm, a change of 1 pH results in a change of concentration by
a factor of 10. For community freshwater it usually hovers around 7.0 (between 6.5 and 7.5),
specialty species such as chiclids and discus have different requirements. Marine tanks are in the
range 8.1 to 8.3.
pH, Changing: Be careful of changing the pH too quickly, most fish will adapt to a stable pH that’s
relatively close to their optimum pH (although fish react differently). Many sources state the
maximum amount of change should be 0.2 in 24 hours. Short of messing with tons of chemicals
or using distilled (or otherwise neutralized) water, its best to keep fish that like pH close to the pH
of your tap water. [see pH Rebound]
pH, Lowering: One way is too use peat, another is to use chemicals but note that many of them
contain phosphorus.
pH, Raising: Increase buffering capacity or use chemicals.
pH Rebound: The effect seen when attempting to change the pH, it seems to change but after a
couple hours it reverts back to the original pH. This happens because of the buffering capacity of
the water, and when this buffering capacity is overcome, pH can change very quickly, so it pays to
be very careful when doing so.
Phaeophyta: A division of marine brown algae.
Phosphate: Chemical symbol PO4, a chemical that spurs algae growth, and is suspected of
decreasing effectivenes of photosynthetic symbiotic algae in inverts. Excess phosphate (> 1
PPM) in freshwater tanks results in algae, and possible dark brown and black coloring of leaves.
Most phosphate tests only test for inorganic forms, whereas a good portion may be locked in
organic forms, but even in this state it utilized by algae (although not directly). Phosphates may
come from tap water, fish food and vitamins, chemicals such as deaminators or dechlorinators,
chemicals that change the pH, or leached from some rocks or gravel. Natural sea water has
about 30 PPB, and excess phosphate ( > 1 PPM) will cause excess algae growth and may retard
calcification.
Phosphor: (1) Chemical symbol P.
(2) May also refer to materials in lighting bulbs that cause the bulb to emit a certain spectrum of
light.
Photosynthesis: The biological process that plants and algae do that utilizes light as an energy
source (about 650 nm), and CO2 to create sugars for energy.
Photoperiod: [see Light Cycle]
Photophobic: Avoiding the light.
Phototropic: Seeks out light.
Phytoplankton: Tiny plant life and spores of larger species living in water, although usually in
reference to marine tanks.
Pi: The symbol that represents 3.14159.
PIP: Particulate Inorganic Phosphorus.
pKa: The pH at which a weak acid or base is 1/2 protonated (i.e. has absorbed a hydrogen ion).
For example, for acetic acid (the protonated form), at it's pKa 1/2 of the molecules are acetic acid
and 1/2 are acetate ions (the deprotonated form). The buffering capacity of a buffer is greatest at
the buffering compound's pKa.
PL Lamps: A type of compact fluorescent.
Plankton: Any number of species of Phytoplankton and Zooplankton ranging in sizes from 0.2
microns to 5 mm, but usually on the smaller side.
Plants: Live Photosynthesizing organisms (Angiosperms) that convert CO2 into O2 during light
cycles and do the reverse during dark cycles. There are many varieties that like water of different
compositions. They will also provide some food for omnivorous and herbivorous fish, and help
reduce ammonia, but also nitrite and nitrate, and provide a haven for good bacteria, and also
many plants contain natural bactericides to deter unwanted bacteria. Also available in plastic.
Plant Tank: A tank primarily intended to grow plants, may have a few fish, generally has
conditions most beneficial to the plants, CO2 injection and generally looks like a jungle.
Plant Micronutrients: Some are, to varying degrees: molybdenum, boron, manganese, zinc,
cobalt, and copper.
Plant Weights: These are usually strips of lead, although they are sometimes made of other
dense materials, used to hold down plants that haven’t fully rooted. [see Lead]
Planted Tank: [see Plant Tank]
Plate Glass: Regular aquarium glass.
Pl*co: A plecostomus catfish, identified in this way because of a superstition about them dying
once identified on the network. Luckily, it hasn't happened to me, knock on wood. [see Net.Curse]
Plecostomus: A bottom dwelling sucker mouth fish, often used to clean away algae in tanks.
Because of their size, and appetite, can often cause problems with plants.
Plumbing: [see Archives]
Plywood: A manufactured wood composed of plies or sheets of wood glued together. Often used
in the construction (when properly treated) of DIY tanks.
PMMA: PolyMethylMethAcrilate, [see Acrylic]
PO4: Chemical symbol for Phosphate.
POC: Particulate Organic Carbon.
Polar: A molecule having a charge so that attracts or repels other molecules.
Polished [Water]: Water than has been thoroughly cleaned. [see Diatom Filter]
Polymethylmethacrylate Acrylic: "Plexiglas" brand acrylic.
Polyps: The “ends” or tentacles or finger-like tips of anemones and corals.
PON: Particulate Organic Nitrogen.
Pond Snails: Common FW snails that will find most plants quite appetizing.
Ponds: A (usually) artificial pond than is kept and filter by a fish keeper for raising cold water
species such as Koi. See newsgroup REC.PONDS
POP: Particulate Organic Phosphorus.
Positive Displacement Pumps :
Post: A message on a newsgroup or the act of "posting" a message to a newsgroup.
Posting to USENET: Requires a news reader, which depends upon the operating system you are
using, and how you are connected to the internet. Contact your system administrator for more
information. Before posting to the group, it would be wise to read the Introduction (posted bi-
monthly), and lurk for a while. To ensure answers to your questions are as good as they can be,
please include as much information about your situation as possible, including tank size, filtration,
inhabitants, ammonia, nitrites, nitrates and anything else.
Post Filter: Generally, any filter which goes after the primary filter, usually for final clean up or re-
conditioning of the water.
Potash: Chemical symbol K2O.
Potassium: Chemical symbol K+, a plant fertilizer. Lack of potassium on plants results in
yellowing of young leaves.
Pounds: (1) A measure of weight.
(2) British currency.
Power Filter: Commonly refers to filters that hang on the back of the tank, and are powered by a
motor.
Power Head: a pump that is usually used on the uplift tubes of a UGF, but has found more uses
as the pumps become stronger.
PPB: Parts per Billion, a measure of concentration.
PPM: Parts Per Million, a measure of concentration, equal to mg/l.
PPT: Parts Per Thousand, a measure of concentration.
Pre Filter: A filter that comes before the Primary filter and filters out the heavy sediment so as
reduce the load in the primary filter, often used in overflow boxes.. [see FILTER FAQ]
Pressure: 1 foot of fresh water is 0.445 psi
Pressure Filter: An external filter similar to a canister filter. Differences?
Precipitate: Usually refers to a chemical which will not dissolve in a saturated solution and so
settles on the bottom of the container.
Primary Filter: The filter coming after the Pre Filter or the one that cleans the most. [see FILTER
FAQ]
Propeller Pumps: A type of water pump
Protein: Any sort of organic waste, before it starts the nitrogen cycle.
Protein Air Stripping: [see Protein Skimmer]
Protein Extractors: [see Protein Skimmer]
Protein Skimmer: A device that utilizes the hydrophilic and hydrophobic nature of many chemicals
and air bubbles to remove organic material (protein) and particulants from the water in marine,
and especially reef setups. Are either airstone or venturi driven, and may be co-current, or
counter current. [see FILTER FAQ]
Pseudomonas: A anaerobic species of bacteria that converts nitrate to nitrogen. Not normally
present in most aquariums. [see Nitrogen Cycle]
psf: Pounds per Square Foot, a scale of pressure, divide by 144 to get psi.
psi: Pounds per Square Inch, a scale of pressure, multiply by 144 to get psf.
PT: Pipe Thread.
Pump: There are basically two types of pumps, air and water [see Air Pumps and Water Pumps]
Pump Head: Ability of a pump to push water straight up.
PVC: Poly Vinyl Chloride, a material used for plumbing parts.
PW: Pet Warehouse, a MO business. [see MO FAQ]
Python: A popular water changer. [see Water Changer]

[Q]: Symbol used in newsgroup subject lines to denote a question is being asked.

[R]: Symbol used in newsgroup subject lines to denote that the topic concerns reef setups.
Raising Young Fish: Depends on the species. Some young need their parents and other need to
be removed (or the parents will eat them). All generally should be kept away from other species,
and you should ensure the water quality is good. Many will need special foods. Refer to a
reputable book or check the archives for tips on breeding common fish.
Ramshorn Snails: Common FW snails that will find most plants quite appetizing.
Ray: Bones in the fins that support the surrounding fin tissue.
RDC: Recessed Double Contact. A type of florescent tube contact base most often seen on
commercial HO lamps.
RE:: Appears in newsgroup subject lines to denote responses to a previous post, usually added
by the users news reader when posting.
Re-Activating Carbon: Impossible, short of having a blast furnace in a vacuum.
Re-Activation Chemicals or Resins: Some are able to be re-activated by immersing in a strong
salt solution for a period of time (such as 24 hours), check you instructions.
Reactor: A chamber in which some gas or solid is allowed to dissolve into a flow of tank water.
Reagent: A chemical used to indicate the presence of another chemical or quality of a solution.
[see Test Kits]
Recharging Resins: Many resins can be recharged using salt solutions, solvents, acids or bases,
depending on the manufacturer.
Red Algae: A type of marine algae, usually occuring because of lack of proper lighting, or an
excess of nutrients.
Red Light: A dim light often used in reef, and marine (and possibly FW) to observing the
organisms at night (their dark-cycle) as this color light does not disturb the fish (they don’t see it
very well).
Redox: [see Reduction Oxidation Potential]
Reducing: [see Reduction]
Reduction: The chemical process in which an reducing agent reacts with another chemical, giving
up its electrons to the other chemical.
Reduction Oxidation Potential: A measure of ability of the water to oxidize organics, in general a
measure of the quality of water, in millivolts. Generally a value between 250 and 400 is good in
reef tanks with 350 being good target, higher may cause tissue damage in sensitive organisms.
Lower values indicate low water quality. Redox may be raised by any filtration system that
improves the quality of the water, especially ozone.
Reef Filter: Was [see Wet/Dry Filter] but now the trend is away from W/D filters for reefs and
replacing them with the Berlin Method.
Reef Tank: A marine tank that contains invertebrates, especially anemones and corals, more
difficult to keep than fish only marine tanks. Some feel that anemones and corals should be kept
separate because of the sensitive nature of corals.
Reefkeepers FAQ: A FAQ expressly for reef setups. It can be found at
ftp.cco.caltech.edu/pub/aquaria/FAQfiles/Reefkeepers. The reefkeeper archives and FAQ can
also be found at percula.acs.uci.edu/reefkeepers.
Reflectors, External: Usually made of aluminum, placed in light fixtures to reflect light towards the
tank.
Reflectors, Internal: Light reflective material placed inside the bulbs. Some feel this does not help
intensity, except for keeping the light “beaming” after distances not normally seen in aquaria.
Refraction: The speed of light through any medium depends on the properties of that medium.
Light travels through glass and through water slower than it does through air. Because of this,
when light crosses the boundary from one medium to another, it tends to bend. This effect is
called refraction. In aquaria this causes objects in the tank to appear to be where they are not,
and under some conditions to see multiple images of the same object.
Refugia (tank): A tank or container usually associated with reef tanks for isolation of some live
stock, usually as protection from predators.
Reservoir: A tank or other container. [see Sump]
Resin: [see Ion Exchange Resins]
Respiration: The process in which oxygen is utilized by an organism, and CO2 is given off.
Reverse Flow Power Head: A powerhead that has the ability to suck water in and propel it down
an up lift tube, operates in reverse of a normal powerhead. Usually used in RUGF.
Reverse Flow Under Gravel Filter: Same as RUGF [see Under Gravel Filter]
Reverse Osmosis Filter: A mechanical filter that is used to purify water, especially for reef and
marine tanks. They use either CTA or TFC, of which TFC produces purer water, more expensive,
and need less replacement, and are recommended; CTA is also only recommended for
chlorinated water because the biological based membrane is subject to deterioration by bacteria.
These systems waste lots of water. Many people combine them with carbon prefilters and DI post
filters. For FW, buffers and trace elements need to be added back to the water.
Reverse Under Gravel Filter: Same as RUGF [see Under Gravel Filter]
RFUGF: Reverse Flow Under Gravel Filter: Same as RUGF [see Under Gravel Filter]
Rhizomes: A part of some plants used to store energy as starches. Occurs as an underground,
thick part of the main stem.
Rhodophyta: A division of red marine algae.
Rift Lake: Certain species of Cichlids from African Rift Lakes that like specific water qualities.
RO: [see Reverse Osmosis Filter]
Rocks: Almost any rock can be added to a fish tank but bear in mind that many rocks will have
different effects on the tank water, some of which may not be suitable for your purposes. The
most common concern is lime in the rock which will increase water hardness, this can be
determined by using the Vinegar Test. All rocks should be rinsed thoroughly to remove any
sediment and organic matter.
Roe: Fish eggs, usually when bound together in a sticky mass.
ROTFL: Rolling On The Floor Laughing.
Rotifer: A type of singled celled organism, often used as food in SW tanks.
RTFF: Read The Fucking FAQ.
RTFM: Read The Fucking Manual.
RUGF: Reverse Under Gravel Filter. [see Under Gravel Filter]

SAE: [see Siamese Algae Eater]
Salicyate: A test for ammonia. Preferred. Compare to Nessler.
Salinity: Usually represented in PPT, subtract 1.1, divide by 1300 and add 1 to get approximate
specific gravity. Usually 35 PPT for typical reef tanks.
Salt: (1) A collection of compounds composed of a cation and an anion with specific chemical
features. It is present in all natural water to some degree, very low in freshwater, and much
higher concentrations in salt water.
(2) Common table salt: NaCl (Sodium chloride), although often contains Iodine (which should
*NOT* be used in aquaria). [see Sea Salt]
Salt Water: A marine setup.
Saturation :The condition that exists for a solution when as much dissolved material is carried by
the solvent as it is capable of dissolving. How much material can be dissolved depends on the
solvent, the solute, temperature, and pressure, and is usually measured in grams/liter.
Scientific Names: Usually, the genus and species (and subspecies if present) of a particular
organism. The complete order in increasing order of specificity is (as roughly exemplified for
humans):
Kingdom: Animalia
Phylum: Chordata
Class: Primaties
Order: Hominidae
Genus: Homo
Species: sapiens
Subspecies: sapiens
Thus, humans are Homo sapiens sapiens. There are some other subdivisions such as
subphylum (vertebrates for humans). The naming is a little different for plants (phylums are called
divisions).
Schooling: Many species need others of their own kind in order to survive. They will often
“school” meaning swim or act together as a group. Many schooling fish kept alone or with
insufficient “friends” may eventually die or at least have a different temperament then when in a
school. Sometimes a lone member may school with others of a closely related or similar species.
With aggresive fish, it is often better to have an odd number of fish, to prevent “pairing off”.
Scrubber: [see Algae Scrubber]
Sea Salt: Any of the varieties of synthetic and natural salt mixtures added the SW tanks. Some
include different sorts of salts, buffers and trace elements.
Sea Water: A marine setup.
Sealant: Use only aquarium quality silicone sealant.
Sediment: [see Substrate] May also refer to large water born particles.
Seed Rock: Live rock that has barely (if ever) been out of water which supposedly has
substantially more living creatures on it than rock that has been shipped dry.
Seeded: [see Cured]
Sessile: Attached by the base, usually refers to invertebrates which can not move.
Setting Up a New Tank: Make sure base is as level as possible and that the base of the tank is
on a flat, level surface. Add a thick board underneath the tank may help, or a cushion of some
sort.
Settling Tank or Chamber: An area, usually related to wet/dry filters, where sediment and detritus
can collect because of low water current conditions.
Sex Ratios: The number of males to females, as found in the wild. This often improves chances
of spawning and reduces intra-species aggresion.
Sexing Fish: This varies from extremely obvious to nearly impossible, and some fish never reach
sexual maturity in captivity. Some can be determined by Sexual Dimorphism, Sexual
Dichromitism, or spawning roles. You should refer to a reputable book.
Sexual Dichromatism: Vairations in body or fin color between the sexes.
Sexual Dimorphism: Variations in body or fin shape or size between the sexes.
SFPM: Surface Feet Per Minute, a measure of surface buffer speed.
SG: [see Specific Gravity]
Shoal: [see Schooling]
Si: Chemical symbol for Silicon.
SiO2: Chemical symbol for Silicon Dioxide.
Siamese Algae Eater: Crossocheilus siamensis, noted for its red algae eating ability, often
confused with the Flying Fox, which are more aggressive and eat little or no algae. Some find
they are prone to jumping.
Silicate: A compound that cause diatomic (brown) algae, it is not readily removed by most RO or
DI filters. Natural sea water levels are 2-3 mg/l.
Silicon: Chemical symbol Si.
Silicone: A material often used to seal and adhere fish tanks and other materials, make sure it is
aquarium safe (free of anything except silicone).
Silicone Tubing: A better variety of tubing that isn’t as likely to yellow and become brittle. [see
Airline Tubing]
Simazine: An algae destroying chemical found in Aquarium Pharmaceuticals “Algae-Destroyer”
suspected of causing some stress to aquarium organisms. [C!]
Siphon: In fish keeping, basically, anything that draws water down by gravity. Many wet/dry filters
use this, as do gravel cleaners.
Siphon Tube: (1) The tube in a gravel cleaner.
(2) The tube in an overflow box. [see Overflow Tube]
Siphoning Gravel or [substrate]: The fish keepers’ process of using a siphon to clean the gravel of
detritus. A must when using an under gravel filter, and often used when high-waste fish such as
goldfish, and in reef tanks before detritus is converted into toxic nitrate.
Siporax: A filter media with a very high surface area.
Skilter: A brand name referring to a device which resembles a power filter, but includes a protein
skimmer. May also refer to any device which has these same properties.
Skimmer: (1) [see Protein Skimmer]
(2) [see Surface Skimmer]
Slime Algae: Brown or red in SW tanks. [see Cyanobacteria]
Slip: A plumbing connection where one tube “slips” into another. Needs to be glued and sealed.
Smear Algae: [see Cyanobacteria]
Snails: Somewhat helpful in the control of algae, dead plant material and detritus, but some
varieties also eat plants.
Snail Control: Remove from plants before adding to tank by hand or chemically, or by treating
new plants to an Alum Bath. Try some Clown Loaches as they have been known to eat snails.
Apparently, lowering hardness will prevent them from forming sturdy shells, Bala Sharks will eat
them, or any other Botia genus fish. [see PLANT FAQ]
SO4--: Chemical symbol for sulfate ion.
SO: Standard Output, sometimes used to refer to NO bulbs.
Soda-Lime Glass: Common aquarium glass.
Sodium: Chemical symbol Na.
Sodium Chloride: Chemical symbol NaCl. Common table salt.
Solid State Ballast: [see Electronic Ballast]
Soft Coral: Corals which may have some sort of internal calcareous skeleton.
Soft Water: Water that has a low degree of Hardness.
sp.: Species not stated.
Spawn: The act that leads to producing eggs or live offspring.
Specific Gravity: A measure the density of a solution or substance divided by the density of pure
water. Increasing solutes, such as salt, in water increase specific gravity. Typically 1.025 for SW
tanks, although many fish may enjoy a slightly lower concentration, don’t venture below 1.017.
Spinner: [see Spray Bar]
Spirulina: An algae often used to provide algae/vegetable food to fish.
Sponge: (1) An open cell sponge filter media.
(2) A marine invertebrate after which (1) is named. Many species do not do well in captivity.
Sponge Filter: A biological and mechanical filter utilizing sponge filter media, usually a Bubble
Filter, but sometimes connected to some sort of water pump.
spp.: Species not stated.
Spray Bar: Part of a wet/dry filter where water both sprays out of and propels a revolving bar.
Compare to Drip Plate.
Spring Water: Although probably better than tap in most cases, does not compare to DI or RO
water.
Sprung, Julian: A reef aquarist and author of the “Reef Notes” column in FAMA and co-author of
“The Reef Aquarium” (which is highly recommended) with Charles Delbeek. He advocates the
Berlin method of reefkeeping.
sq.: Square, or to the power of 2, often written as ^2, refers to area.
Sr: Chemical symbol for Strontium.
Stand: [see Tank Stand]
Stress: What inappropriate tank conditions (such as temperature or levels of ammonia, etc.) do to
fish, which usually leads to weird behavior, illness and even death.
Stony Coral: [see Hard Coral]
Strontium: Chemical Symbol Sr. Useful in reef tanks for hard corals. Levels of about 8 to 10
PPM in natural sea water.
Strontium Chloride: A common chemical used to add Strontium.
Starting a Tank: The tank should include all the hardware and substrate and water (that has been
treated for chloramine) and a couple small (inexpensive) fish are added to start the cycling
process. [see Cycling] [see BEGINNER FAQ]
Submersible Filters: [see Internal Filters]
Submersible Heater: A heater that is (usually) fully submersible in the tank water, which is
preferred. Make sure is it suited for salt water when using it in a brackish or marine tank.
Submersible Pumps: Pumps that can be (usually) fully submersed in water, this usually leads to
quieter operation but will heat up the water to some extent. Sump pumps are usually submersible.
Substrate: Any of number of materials that cover the bottom of the tank, and generally serves a
purpose, although in simple fish-only fresh water tanks may only serve as decoration. Special
substrates of gravel, clay and peat are common in plant tanks, whereas marine tanks have
crushed coral. Reef tanks may not have any substrate at all.[C!]
Substrate Depth: As a general rule 2 to 4 inches.
Substrate Heating: A system that utilizes heated coils under the substrate to circulated water for
plant growth.
Sulfates: Chemical symbol SO4--.
Sump: [See Sump Pump] or sometimes the container where a sump pump is located.
Sump Pump: A type of water pump often places in a wet/dry filter for returning water to the tank.
Sunlight: Direct sunlight on a fish tank will usually result in excess heat buildup, and excess algae
growth. It is to be avoided.
Sunrise/sunset Simulation: In aquariums with intense lighting (often plant or reef tanks) or light
sensitive organisms, it may be best to simulate sunrise and sunset by any number of means.
Some of these include dimmers that automatically brighten and darken the lights at appropriate
times, using ambient light in the room (to reduce sudden dark to light), or having banks of lights
come on in stages (i.e. staggered). Some species become vary stressed and may panic when
sudden light/dark changes occur.
Super Actinic: [see Actinic 03]
Supersaturation: When a solution is carrying more solute then it is normally capable of at at
particular temperature and/or pressure. This is usually accomplished by heating a solution to a
temperature that permits solution and then dropping the temperature to below this point. These
two factors tend to cause hot tap water to be supersaturated with O2. These solutions are very
unstable and tend to precipitate the solute if any nucleus for crystal formation is available.
Surface Agitation: Used to increase absorption of O2, or off gas unwanted chemicals. Note that
some species like more or less surface agitation.
Surface Extractors: [see Protein Skimmers]
Surface Skimmer: A device that draws water primarily from the surface, usually to remove
surface slicks.
Surface Slicks: The slicks, sheens or thin scrum found on the surface of tank water, usually
composed of organic compounds. Note that these can seriously reduce the amount of oxygen
exchange between the water and the atmosphere.
Surfactants: A substance which decreases surface tension of water (i.e. the tendency of water to
stick to itself). These are molecules which have a non-polar end (which interacts with non-polar
substances) and a polar end which interacts with water. In aquaria, this usually comes up in
discussions of protein skimmers, as surfactants help them foam.
SW: [see Salt Water]
Sweeper Tentacles: Coral polyp growths which are used for aggresive and defensive purposes.
Swim Bladder: An internal organ which allows fish to maintain proper position in the water.
Swords: Genus Echinodorus. A type of FW plant often kept by aquarists.
Symbiotic Algae: The algae found in some invertebrates that works with the invert to create
energy through photosynthesis.

T-8: A designation for florescent bulbs the states diameter in 1/8ths of an inch, so a T-8 bulb is
8/8ths or 1” in diameter. Generally, NO T-8 bulbs are 15w per 18 inches of length.
T-10: A designation for florescent bulbs the states diameter in 1/8ths of an inch, so a T-10 bulb is
10/8ths or 1 1/4” in diameter.
T-12: A designation for florescent bulbs the states diameter in 1/8ths of an inch, so a T-12 bulb is
12/8ths or 1 1/2” in diameter. Generally, NO T-12 bulbs are 20w per 24 inches of length.
Tail Fin: [see Caudal Fin]
Tank: Fish tanks are normally made of glass, and acrylic, and some DIY materials. The generally
take one of a dozen or so shapes. This makes it easy to fit hoods, UGF filter plates and other
hardware. Long tanks are best for larger fish, and taller tanks can support fewer fish than a longer
tank of similar capacity.
Tank Stand: Must be level, stable, and able to support the weight of the tank. Many kinds are
available retail, MO and DIY. [see Weight of Tank]
Tap Water: The quality of tap water varies from place to place and from season to season.
Those with municipal water usually have to be concerned with chlorine, ammonia and chloramine,
whereas those with well water usually have to be concerned with overly hard water, particulants,
pesticides and parasites. Or your water may have different problems. Those with municipal water
can usually check with the local water works to find out what’s been added, chemical or otherwise.
Many products are available from treating many of these problems, and if your water is bad
enough you may wish to consider buying distilled water, or using an RO or DI unit.
TAT: Theil Aqua Tech.
Teflon Tape: A tape used on plumbing threading connections to help keep connection tight and
provide some seal.
Temperate: Being of an climate that has a temperature somewhere between Tropical and Cold
water, and generally has larger temperature variations than tropical. There are many species
suited for this type of climate.
Temperature: Variations of more than a couple degrees, over a hour or so, can cause stress and
should be avoided, generally a slight cooling is accepted easier than a comparable warming. A
few too warm and fish metabolism increases, increasing their requirement for O2, etc. Generally a
heater is used to maintain a warm enough temperature, although sometimes cooling is required.
Community fish will do well at 76 to 78 degrees, as will most marine and reef fish, although it is
best to check a reliable book for the temperature range desired by your organisms.
Tempered glass: A type of glass that has improved strength, often found on the bottom of large,
tall, or oddly shaped tanks. Never try to cut or drill.
Terrarium: A micro environment usually consisting on terrestrial plants and animals, although
may have some bodies of water in it.
Test Kits: Everyone will want a thermometer. Basic freshwater keepers may need only ammonia,
GH and pH kits, whereas some may also want KH, and if keeping a plant tank, iron and CO2.
Basic saltwater tests are ammonia, GH, alkalinity, pH, and salinity (a hydrometer). For both FW
and SW, a nitrate kit can help determine when nitrogen cycle has completed and after that, will
help measure how well the water change regime is fairing. Reef keepers will need, in addition to
all saltwater tests, low range nitrate and calcium, but most will also want ORP (Redox), iron, and
copper. Either FW or SW keepers having problems with algae may want phosphate tests, or
concerned with dissolved oxygen an O2 kit. Those keeping brackish tanks will also want a salinity
test.
Tetras: Sub-order Characins. From South America and Africa. Contains many very common
aquarium fish, most are small and schooling, but includes also such fish as Piranhas, Pacus and
Silver Dollars.
TF: (1) Top Fathom
(2) [see Trickle Filter]
TFC: [see Thin Film Composites]
TFH: Tropical Fish Hobbyist, a magazine.
TFP: That Fish Place, a M/O business. [see MO FAQ]
Thallus: The physical structure of marine macro algae.
Thermometer: A device for measuring temperature, a *must* for every aquarium.
Thiel, Albert: A aquarist, and writer of many books on the topic, and producer of many aquarium
products. Opinions vary on his methods. [C!]
Thin Film Composites: A material of which some RO filter membranes are made of, and because
of its efficiency, produces water that is _NOT_ fit to drink. [see Reverse Osmosis]
Thread Algae: Long thin strands up to 10 inches or more, possible caused by excess iron.
TIA: Thanks In Advance
Titanium: A very strong metal, also one of the few metals that can be used in aquaria without it
oxidizing or leaching into the water.
Tonga Rock: Premium LR from Tonga. [see Live Rock]
Topper: A device which monitors level of the water in the tank and automatically adds water if
necessary.
Trace Elements: The very small amounts of different chemicals and elements that certain
organisms. Plants trace element deficiencies shows itself as yellow, glassy, brittle leaves that die.
Transporting Fish: Most medium sized fish should get their own bag. Their should be enough
water for the fish to be completely immersed, and able to turn around, plus a little. The important
thing is air trapped in the sealed bag. For long trips ask your local aquaria dealer to add O2.
Keep all the bags in a cooler to maintain temperature. Beware getting them too hot, the fish
metabolism will increase and the maximum O2 concentration will drop yielding suffocated fish.
Try not feeding them for 36 to 48 hours previous to eliminate waste from bags on longer trips. If
temperature is a concern, small amounts of ice water or warming pads in separate bags may help
but don’t over do it.
Tri-Band: [see Trichromatic]
Trichromatic: Having three phosphors in lighting so as to reproduced the Sun’s natural light. [see
Full Spectrum]
Tridacnid Clams: Invertebrates of the family Tridacnidea, and two genera, Hippopus, and
Tridacna and have zooxanthellae. They are kept in reef aquariums. They are filter feeders, but
also take up disolved inorganic nitrogen, and phosphate.
Triphosphor: [see Trichromatic]
Trickle Filter: [see Wet/Dry Filter]
Trickle Media: Filter media used in a wet/dry filter usually with a large surface area exposed to
the air. [see Wet/Dry Filter]
Tritrate: Usually refers to test kits in which a reagent is dropped into the sample until a color
change occurs. Generally more accurate than color comparison tests.
Triton: A specific brand of fluorescent bulbs that are known for their spectrum, high output, and
long lasting.
Tropical: Coming or similar to the Tropics, generally having a continually warm temperature.
Tubifex Worms: Are Tubific worms of various species up to 3 or 4 inches, used as live or freeze-
dried food.
Tufa Rock: Usually safe for aquariums. Some suspect a new “red” variety may contain iron
which may be better for FW plant tanks, and not so good for SW tanks (helps algae). [see Rocks]
Turbidity: Not clear, water cloudiness caused by suspended sediment and organics. Note it will
reduce penetration of light intensity into tank. Can be reduced by mechanical and biological
filtering, and a general improvement in water quality.
Turbo Snails: Turbo spp. A SW microalgae eating snail that is highly recommended for reef
tanks. Stocking levels have been suggested on the order of 1 snail per 6 to 10 gallons because
they can get much larger.
Turf Algae: Short fuzzy algae in SW tanks. Can be avoided by keeping tank dark while cycling,
keeping nitrates and phosphates low, and keep tank free of detritus. Some herbivores and snails
will eat it before it gets too long, or remove by hand.
Turf Scrubber: [see Algae Scrubber]
Turn Over: The process by which some fish, snails or other organisms will dig up, move around,
churn, or otherwise mix the substrate so as reveal trapped detritus and prevents anaerobic areas.
This is especially useful when using UGF or having a reef tank with a substrate.
Turnover Rate: The number of times the volume of water in the tank passes through the filtration
system in an hour. For most aquariums the minimum is about 3 to 4, with no practical upper limit,
except when fish are distressed by the water currents (some may reach 8 to 9 times). [see FILTER FAQ]
Tungsten Halogen lights: High wattage incandescence commonly sold as Halogen room lights,
run very hot, not used often in fish keeping.

u (or Greek U): Micro or Micron.
ug: micrograms, 1/1000 of a gram.
UGF: [see Under Gravel Filter]
UK: United Kingdom, Great Britain.
UK Measurements: 1 US Gallon 1.201 UK Gallons
1 Liter 0.568 UK Pints
Un-cure [Live] Rock: [see Cure Live Rock]
Under Gravel Filter: A plastic filter plate that covers the entire bottom of a tank over which gravel
is placed. Usually water is sucked down through, or sometimes pushed up through [see RUGF]
by use of power heads or airstones, utilizing the gravel bed as a biological filter media. There is
some controversy over there use in planted tanks, or for long term use. That’s rather academic,
popular opinion is against UGFs as compared to more favorable filtration systems, especially for
SW and reefs. [C!]
URI: A maker of specialty Reef bulbs, among other things.
US Measurements: Measures of Weight
1 ounce oz 28.35 grams
16 ounces 1 pound
Measures of Volume
1 cup 236.8 ml
2 cups 1 pint
2 pints 1 quart
4 quarts 1 gal. 3.8 liter 231 in^3
1 teaspoon tsp. 5 ml 1/6 fl. ounce
1 tablespoon tbs. 3 tsp. 1/2 fl. ounce 15 m l
1 fluid ounce 2 tbs. 6 tsp. 29.6 ml
1 cup 8 fl. oz.
Measures of Length
12 inches 1 foot
3 feet 1 yard
Measures of Area
1 sq. foot 144 sq. inches
1 sq. yard 9 sq. feet
USENET [News]: A system across the internet that allows people to post messages and replies
to messages (often called “posts”) to an electronic bulletin board, seperated into catagories called
News Groups. Requires a News Reader. See your system administrator.
USP: US Pharmacopeia, a standard of quality, purity, etc.
UV: Ultraviolet, a range of light.
UV-A: 375 nm to 400 nm light, does not irradiate, but will pass through water and glass.
UV-B: 280 nm to 315 nm light, can cause irradiation damage, but will be filtered out by glass and
water.
UV-C: 200 nm to 280 nm light, can cause severe irradiation damage, but will be filtered out by
glass and water.
UV Filter: [see UV Sterilizer]
UV Shield: Some sort of transparent shield placed between the aquarium and some lights
because they produce too much UV.
UV Sterilizer: Not really a filter, but it does remove harmful organisms from the water by killing
them with radiation from a UV source of about 256 nm (UV-C range). These bulbs have a life
expectancy of about 6 months.
Ultraviolet: A range of wavelengths of light below the blue spectrum.

Vacation Feeders: [see Feeder Blocks]
Valonia Algae: A marine algae that supposedly will be eaten by large sailfin tangs (Zebrasoma
Desjardinii).
Ventral: Refering to the bottom of the fish.
Venturi Skimmer: A Protein Skimmer that uses the venturi effect of a power head to create
bubbles.
Venturi Effect: As applied to fish keeping, a process by which air is sucked into a tube of fast
flowing water causing air bubbles.
VHO: Very High Output, as refers to lighting. 1500 mA. They generally about 3.5 to 4 times as
much wattage as same length NO bulbs. Although it has suggested they are not as efficient as
(per watt), and tend to have a shorted life span than SO or NO bulbs.
Vinegar Test: A simple test for lime (which will increase hardness of your tank water) for use on
rocks and gravel. Simply drop as pure and strong vinegar as you can find onto the sample, and if
it bubbles it indicates the presence of lime. Note that having hard water is good for some species
and this should be checked using a good fish reference book.
Vitamins: Basically, any micro nutrients that may be required by an organism. Products are often
sold specifically for some inverts or other fish that may need supplimental nutrition.
Void Space: A term used to describe the air space of a biological filtration media, especially those
used in trickle filters. Adequate void space is necessary for good gas exchange.
Voltage Eliminator: [see Grounding Probe]
Voltage Lowering Devices: [see Grounding Probes]
Volts: A measure of electric force.
Volume: For cylinders, area of the circle * length. For cubes, etc., area * height.

W: [see Watt]
Warm Light: Refers to light with a spectral output of 3400 down to high 2000’s Kelvin. They tend
to have a yellow-white color.
Washing Gravel: [see Gravel Vacuum]
Water: Chemical symbol H20. [see WATER FAQ]
Water Changers: A system of tubing and devices, of varying complexity, for the automation or
ease of water changes.
Water Changes: [see Periodic Water Changes]
Water Clarifiers: Products which normally include coagulant to remove fine particles through
normal mechanical filtration.
Water Conditioners: Chemicals that remove or de-toxify other chemicals and metals, promote fish
slime coat, or contributes bacteria or enzymes to the water.
Water Conditions: The measure of various aspects of water quality, such as temperature, pH,
hardness, ammonia, nitrite and nitrate, among others. Others for marine and reef tanks.
Water Polisher: An extremely efficient water cleaner [see Diatom Filter]
Water Pumps: A pump which moves water. There are many kinds of pumps for different
applications.
Water Purifier: [see RO] or [see DI]
Water Softener: A chemical filter which reduces water hardness.
Water Quality: A general phrase the takes usually a non-quantitative value of the water, and its
relative “goodness” to “badness”. Things like ammonia, nitrite, nitrate and others point to poor
water quality, while saturated O2, correct alkalinity, hardness and others point to good water
quality. In good water quality, organisms with thrive and flourish instead of just sustaining,
whereas in poor water quality, organisms will at best just sustain, but will probably become
stressed, ill, and eventually die. Water quality is improved by improved filtration, water changes,
and watching what is added to the tank (food, water, additives).
Watts: (1) A measure of electric power, volts * amps. [see Electrical Usage and Cost]
(2) Used in heaters to denote heating power. [see Heaters]
Wave Makers: Electronic devices which control power heads or pumps in reef tanks to simulate
changing currents.
Weekend Feeders: [see Feeder Blocks]
Weight of Tank: Including rocks, tank, water, and everything else is approximately 10 pounds per
gallon, unless the tank has exceptional amount of rocks like reef tanks (which may approach 15
lb. per gallon).
Weight of Water: 8.57 pounds per gallon.
Wet/Dry Filter: A filter most often used in Marine tanks, but sometimes in Reef tanks, that has a
device that trickles water over a large amount (usually 1-2 gallon or more) of non-submerged
biological trickle media (the dry phase) and then through a submerged biological media (the wet
phase), and then the water then travels through another chamber (often used for chemical
filtration) and then to a sump. They generally have a high gas exchange capacity. There are
many different types and styles of wet/dry filters, and DIY plans for many can be found in the
archives.
Web: [see World Wide Web]
Web Browser: A program which allows you access to Web Resources, such as Mosaic or
Netscape. See your system administrator.
Web Resources: Any resource available through the internet Web, such as HMTL pages, text,
graphics, and sound.
WD: [see Wet/Dry Filter]
Whiteworms: A live or freeze-dried food, Enchytraeus albidus, sizes to about 1 inch.
World Wide Web: A internet resource that is utilized by a Web Browser, as applies to fish
keeping, browse the following resources:
http://www.actwin.com/fish/index.html
http://marge.phys.washington.edu:80/pub/fish/
http://www.ncf.carleton.ca/freeport/social.services/orgs/acquat-con/menu
http://trans4.neep.wisc.edu/~gracy/fish/opener.html
http://www.mcom.com/fishcam/fishcam.html
http://elmendorf.camb-lads.loral.com:8080/~rg/aquarium.html
ftp://ftp.cco.caltech.edu/pub/aquaria
ftp://ftp.netcom.com/pub/hurleyj/www/fish.html
http://akebono.stanford.edu/yahoo/Entertainment/Animals__Insects__and_Pets/Fish/
WTA: Wet Thumb Aquatics, a MO outfit [see MO FAQ]
WTB: Wanted To Buy.
WWW: [see World Wide Web]
W3: [see World Wide Web]

X
I can’t think of one X word...
Y

Yeast Method: DIY method of generating CO2 to stimulate plant growth. [C!]
Yellow Water: Usually only a yellowish tinge, often caused by too much organics in the water.
Can be reduced by improving filtration, water changes, reduction of biological waste (such as
excess food or rotting plants), and GAC.
YMMV: Your Mileage May Vary, basically just because something works well in one situation,
does not mean it will in another.
Yolk Sac: The substance in eggs or which in eggs are placed which serves are the food source
for the un-hatched young.

Zeolite: A mineral that softens water and adsorbs ammonia [see Chemical Filters] , for fresh water
only.
Zooplankton: Tiny animals and larvae of larger species living in water, usually in reference to
marine tanks.
Zooxanthellae: The symbiotic yellow or brown single celled algae living in some invertebrates,
who supply mostly glycerol and acetate to the host. In corals they are of of Symbiodinum spp.
Zoochlorellae: The symbiotic green single celled algae living in some inverts.
Zygote: The combination of the two gametes needed to develope a new individual.

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Thursday, October 22, 1998

Aquaria Glossary

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Thursday, October 22, 1998

Aquaria Glossary

No comments:

The Exchange

Features

Pipes

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The Observatory

The MessHall

The Isles...

Cory Search

FishRoom WebSide Companion

RTO Announce E-List

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