[leebca]

There are many terms I and other aquarists use that the hobbyist may not fully understand or misunderstands. This is a short glossary of some FOWLR terms (I often use) relating to the marine hobby, which I hope will help the marine hobbyist and marine aquarist. Reef terms are only included if they are also used in FOWLR marine systems. If you note an error, please point it out to me.


Acclimation (acclimate) - The process of the marine life form getting accustomed to captive life. The process begins by getting the fish (for instance) used to quarantine tank water (see: A Fish Quarantine Process Acclimation continues as the fish (for instance) grows accustomed to its owner, foods provided, tank mates, etc. The specimen may take hours, days, weeks, months to properly acclimate, or literally never acclimate. Deaths can occur from specimens that won’t/don’t acclimate or which have been initially improperly acclimated to captive salt water life.

Aerobic - Requiring oxygen for a process (such as respiration).

Aggressive fish - I classify most marine fishes into one of three groups relative to how they act in captivity. The three groups are Aggressive fish, Assertive fish, and Shy fish. They are defined by 3 main responses. The aggressive fish will recognize the feeder and swim forward without any hesitation. The aggressive fish will eat and if it can, it will try to get all the food. The aggressive fish usually swims in the open and watches what is happening in (and sometimes outside of) the tank. This fish doesn’t get along with most others, if it is an active swimmer. If the hobbyist/aquarist puts a gloved hand or equipment into the tank, the aggressive fish will just as soon bite as watch what is going on.

Ammonia wastes - These are chemicals containing ammonia produced by marine fish and some marine life forms, in their normal excrement. Ammonia is formed by the breakdown of organic material, deadly to marine fishes in very low concentrations. More than just marine fish produce these wastes. Such wastes are produced by bacteria and other microbial life forms for example, when the necessary nutrients (organic material like leftover fish foods) are available to them.

Anoxic - A general term used by aquarists (sometimes) to describe a place in the marine aquarium when oxygen is in short supply – not void of oxygen; just low in oxygen – enough so that denitrification may occur. See: Denitrification.

Artificial rock - Cement or man-made shaped materials to act like live rock. Called ‘homemade rock’ too. Even though artificial rock may be placed next to live rock, it will only have the bacteria, algae, pods, and mobile organisms that can move from the live rock to artificial rock. Some artificial rock is placed in the ocean where it can age and turn into a version of live rock. This is aquacultured live rock. The diversity of life on and in this rock depends upon a few factors such as the kind of material, the number of years it sat in the ocean, and the marine lifeforms in the area/environment. The concept of putting barren artificial rock or base rock next to live rock in order to ‘make’ live rock out if is a false hope. The base and artificial rock will only take on the organisms that are mobile, bacteria, algae, etc. and never truly become ‘live rock.’ See: Live rock

Assertive fish - I classify most marine fishes into one of three groups relative to how they act in captivity. The three groups are Aggressive fish, Assertive fish, and Shy fish. They are defined by 3 main responses. The assertive fish recognizes the feeder and will usually come forward at feeding time or perch/take a position ready to eat. It eats well with other fishes, neither pushing other fishes away, stealing food, but getting its share. But you can usually find this fish right where the food drops into the aquarium. If the hobbyist/aquarist puts a gloved hand into the aquarium, this fish may come forward to investigate and/or then retreat to a safe place to watch what is going on. If the hobbyist/aquarist or another fish gets close to it or its territory it may make signals to warn the intruder off.

Base rock - There is no standard definition for this rock. The hobbyist and aquarist must ask what this means to the seller or provider. In general terms, it is marine suitable rock void of non-microbial life. (Remember, the bacteria responsible for nitrification will attach to any surface area). Some though prefer to consider base rock as rock that contains bacteria, coralline algae and other algae, but I don’t subscribe to this definition. Some people don’t make much money calling their rock for sale, ‘base rock’ so there is a push to call it live rock as soon as the seller can ‘get away with it.’ See: Live rock.

Berlin system - It is a marine system consisting of live rock and live sand as its biological filtration, with circulation to move the wastes to the filter bacteria. See Flow rate, Biological filter, and Live rock.

Bio-load (bioload) - The biological impact put (in this case) onto the marine system. From fish, the biological impact includes gas and solid and liquid wastes. What most hobbyists don’t realize is that the bacteria that handle fish wastes also produce their own biological impact – the consume oxygen and generate their own wastes. Other sources of the bio-load comes from foods and things added to the system, as well as those things that are dying. The amount/quantity of bio-load a marine system can handle is determined mostly upon the biological filter used, circulation, filtration and add-on equipment. See: Fish stock limit.

Biological filter - The name given to the process where bacteria convert ammonia wastes to nitrites and then converts nitrites to nitrates. This part of the biological filter is called nitrification. Some aquarists also think of a part of the biological filter as converting nitrates to nitrogen gas and other chemicals. This part of the process is called denitrification. When asked, ‘What kind of biological filter are you using’ it means are you using live rock, an under gravel filter, a canister filter, etc. to hold the bacteria that perform the nitrification process.

Bristle worm - A marine animal that often come with live rock. They burrow into the substrate, but (without any threats from fish) will swim into the open to find new eating grounds. In the group known as Polychaetes, bristle worms number at least 10,000 species. Very few are bad; some can sting a human bare hand; others can damage corals; but most, especially those of the Eurythoe sp. are very useful. They are usually less than a few inches long (down to less than half an inch), pink to orange with white bristles, sometimes with a bluish line running along the center of the body. They eat detritus, pods, and keep the substrate moving around and provide additional food for some fishes that eat them. Be thankful if you have them. However, if there is an exceptionally large number of them, that is usually a sign there are too many nutrients in the system for them. Don’t handle live rock and sand with bare hands, or put bare hands into the marine system where they are living. (See Bristle Worm Photo).

Carnivore - Marine life (fish in this case) that obtains its protein from animals. Such fishes eat other fishes and other animal marine lifeforms. In captivity, some will eat sea vegetables, too, but at least a large portion of their diet must be whole animal sea foods.

Chemical filter - A means to remove wastes from the marine system by use of reactions. Sometimes also includes absorbents (like resins and activated carbon) which sometimes are more ‘mechanical’ than ‘chemical’ in nature. Such filters include those that remove nitrates, phosphates, etc. by ‘reactors.’

Circulating pump(s) - Sometimes called ‘powerheads’ these pumps circulate the water inside the display tank. They are located inside the display tank to move water around to prevent ‘dead spots’ where wastes may accumulate, and to keep the surface of the water in motion to aid in gas exchange. They are important to boost the flow rate in the display tank. See Flow rate.

Cleanup crew - Those marine lifeforms introduced into a marine system to perform one or more functions. These lifeforms may consume nutrients, algae, left over foods, detritus, detritivore, and microbes to name a few. They may perform certain needed or desirable functions like stirring the substrate. These life forms include snails, worms, some detritivore marine lifeforms, crabs, nudibranch, urchins, starfish, cucumbers, etc.

Curing live rock (cured, cure) - With regards to marine systems, this is the process to get rid of decomposing and dead organic materials in and on live rock. There is die off at almost every stage of handling of live rock coming into the retailer. If put directly into an aquarium, it would create a lot of pollution and slow down the maturing process of the aquarium. Thus curing such rock outside of the aquarium is usually the best course. If the rock is sold a ‘cured live rock’ the buyer should ask what this means and whether or not some curing will still to be done, and if so, to what extent. Minor curing in a newly setup (no fish or higher/sensitive inverts in yet) aquarium is okay, but no curing of rock should be done in an established marine system.

Deep sand bed - A term to describe a substrate in the marine system that is deep enough to create anoxic conditions so that denitrification may occur. The particle size and depth are important to the efficiency of the deep sand bed, sometimes abbreviated DSB. These can be setup in the display tank, sump, and/or refugium. They usually begin at about 4 inches deep and go as deep as 6 inches. Its depth and efficiency is based upon particle size. See: Anoxic, [i]Denitrification[i/], and Marine system.

Denitrification - The process of converting nitrates into nitrogen gas and other compounds. This is a part of the nitrogen cycle performed by bacteria that don’t like an environment with oxygen in it. These bacteria are anaerobic in nature, but many will survive in an anoxic environment. This process may occur in areas of the aquarium when oxygen is in short supply, such as a deep sand bed, inside or in crevices of live rock, where live rock meets the substrate where there is very little water flow, and artificial areas such as a nitrate reactor.

Detritivores - Are animals that feed on detritus and recycle the nutrients therein.

Detritus - Decomposing organic materials. Mostly made up of left over food, dead algae, dead microbes, and marine lifeform wastes. Usually accumulating in the areas of the marine system where water flow is low to ‘dead.’ Often collected on a mechanical filter. It may appear brownish in color with a somewhat ‘fluffy’ appearance when laying in a corner. It is a breeding ground for bacteria which consume oxygen and produce additional wastes in the marine system. Under certain circumstances where water may be anoxic, the bacteria may produce harmful hydrogen sulfide gas (smells like rotten eggs) which can wipe out an entire marine system.

Dither fish - A fish that comes forward to see its owner, doesn’t hide much (usually swims in the open), peaceful, and eats well, yet isn’t overtly competitive with tank mates. This fish is put in with a timid fish to teach it to be less afraid and to eat. I keep dither fish in my QT. They are disease-free. When I need to acclimate a timid or less hardy fish, I put it in with the dither fish or fishes.

Filter sock - A useful type of mechanical filtration mechanism. A filter is fashioned into what looks like a long tube (sock) closed at one end; open at the other. The open end is fitted into a mechanical filter or is placed in-line of a marine system to collect solids. The open end is fitted to a plastic ring which fits specific equipment, or is fitted with a drawstring. Often, a filter sock is placed on the end(s) of the return plumbing from aquarium overflows where aquarium water is gravity fed into the sock. Socks come in different sizes and materials. They also are offered in different filtering ability, usually given in microns or mesh, controlling what size particle is allowed to go through the sock material. See: Micron, and Mesh.

Fish stock limit - The maximum quantity of fish that may be put into a marine system. This quantity is properly defined as the amount of total bio-load the fishes put on the system and the system’s ability to handle that bio-load. First consideration: A larger aquarium with advanced filtration and equipment will handle a larger bio-load than a nano aquarium of small volume with only basic filtration. Second, is that every fish of the same length does not have the same biological impact on a system. A ‘thick’ or ‘heavy’ fish (e.g. Grouper) does not have the same biological impact as a naturally thin fish (e.g., a Butterflyfish) even though they are the same length. Third, stocking limit needs to take into account the swimming space the particular fish species is known to need. For instance, a Tang should be provided no less than a 6 foot long aquarium and open swimming space for them to do well in captivity. Thus, considering the above, a stock limit cannot be given in terms of inches of fish. See: Bio-load and Fish Stocking Limit - for FO and FOWLR

Flashing - The marine fish that is scraping itself on aquarium decorations or the substrate appears to be ‘scratching’ an itch. This action causes the belly of the fish to turn sideways. Since the belly of the fish is sometimes lighter in color than the sides of the fish, the fish appears to be ‘flashing’ like a light signal. Hence the behavior was given this name.

Flow (circulating) rate - The measure of how much water is flowing/circulating in the display tank. Aquarists put this into terms of ‘turnover’ or how many times the volume of the system is circulated in the display tank. The (total) flow rate is the sum of the flow rates created by each pump. Each (inside) circulating pump flow is added to the return pump flow to provide a total flow rate in the display. For FOWLR the desired flow rate is no less than 8. For a reef tank, the desired flow rate is no less than 16. That is, 16 times the volume of the system is circulated in the display tank every hour. A 100 gallon FOWLR marine system is recommended to have no less than 800 gallons per hour flow rate.

FOWLR - Acronym for: fish only with live rock. The live rock helps provide the function of sponsoring the bacteria that contribute to the nitrogen cycle, both nitrification as well as some denitrification. For the most part, the marine life in and on the live rock comes and goes both in kinds and numbers. The rock is usually there for appearance, aquascaping to provide the fish with a familiar surrounding, provide fishes with hiding places and territories, and performing biological filtration. The purpose of this marine system is to maintain marine fishes. See Live rock.

Head (back) pressure - The back pressure on a water pump or pressure source. It is resistance. A pump that is listed with a flow rate must also come with an indication of its flow rate at a specific head pressure, to be meaningful. Head pressure is often given in terms of ‘feet’ to raise the water. So a pump with a flow of 100 gallons per hour at 6 feet would mean that if the pump had to pump water up 6 feet into the air, the flow rate of that water would be 100 gallons per hour. If the height is under 6 feet, then the water would move faster or the flow rate would go up. If there is more than 6 feet of back pressure on the pump, then the flow rate will go down. Other things create head pressure. Every elbow in the plumbing can be counted as 1 foot back pressure. Raising water is straight 1 foot for every foot the water goes up. Length of plumbing also creates resistance such that about 1 foot of back pressure is given for every 10 feet of plumbing. A narrowing of the pipe diameter creates back pressure too. In this way a more or less reliable flow rate of an installed return pump can be estimated when the pump manufacturer supplies a graph showing the pump’s performance/flow rate at different head pressures/feet, and the back pressure in feet is estimated closely.

Herbivore - A marine life (fish in this case) that obtains its protein primarily from sea vegetables. Although in captivity most herbivores will act as omnivores, the goal is to be sure they get at least 65% of their protein from sea veggies.

Hyposalinity - Also known as osmotic shock therapy. The salinity of the salt water is lowered below normal ranges in order to treat only one kind of parasitic attack on marine fishes: Marine Ich (Cryptocaryon irritans). Effective hyposalinity for curing fish of Marine Ich is 1.008 to 1.010 sp. gravity units controlled by the use of a refractometer. See: Hyposalinity Treatment

Koi - A mutant carp. Freshwater. Avoid at all costs.

Live rock - There not being a standard definition, it ranges from what some would call base rock to true living rock. At high end of the spectrum is rock that has been in the ocean/sea for dozens of years, containing a diversity of lifeforms inside and outside of the rock. This rock contains some marine lifeforms that can’t reproduce in the aquarium, so once they die, they will not be replaced. These creatures will not populate artificial rock put next to them in the aquarium, because they are not mobile AND they don’t reproduce in the aquarium. This true living rock would require it be shipped in water to preserve the greatest diversity of life it has to offer. Shipping water by air is expensive. Most live rock is a step down from this, shipped moist but not in water. Those organisms that cannot handle exposure to air (e.g. many sponges) die. This live rock may still contain many of the above mentioned marine life that cannot reproduce in the aquarium. The rock is still called ‘live rock’ but isn’t up to its full potential. Still this and the ‘true live rock’ described above are able to perform the denitrification function in the marine system, and they are desirable for this and other reasons. Somewhere near the low end is rock that just has bacteria, algae (coralline and other) and pods with a small percentage of chance of another organism. This rock will not be fully able to perform the quantity of denitrification the other live rock can, but still has a value. At the low end is rock without algae or lifeforms other than bacteria (base rock). There being no standard, ask what the ‘live rock’ means to the seller and either see the rock in person, photos, or have it described in terms of what life is likely in and on the rock. See: Artificial rock, Base rock, and What is Live Rock, Anyway?.

Macro algae - In the marine system, this is algae large enough to see the stems and/or leafy portions of the plant with the unaided eye. They include such plants of the [i]Caulerpa sp.[/] Many are eaten by omnivore and herbivore marine life.

Marine aquarist - I use this term to mean seasoned people who are successful in the husbandry of marine life in the home/professional marine system. They have learned most of the terms in this Glossary, and know most about keeping marine fish and/or marine invertebrates. Their specimens thrive, and they have a ‘correct’ general understanding of what is going on inside their marine system as far as science and research has proven. These people provide the best nutrition and environment for their specimens, including excellent water quality. But I think, from a personal perspective there are two more attributes a marine aquarist needs in order to be called an ‘aquarist’ by me. One is this: ***They do no harm to marine life***. By this, it is meant that they don’t knowingly bother, stress, or cause pain to the marine life. They do what’s in the best interest of the marine life. For instance, no way would a true aquarist treat all newly acquired marine fish with copper ‘just to be sure’ the fishes don’t have Marine Ich. Copper stresses the fish so fish that don’t need it are being stressed. The second attribute of an aquarist is: ***Acquiring specimens suitable for the marine system***. By this, it is meant they don’t put Tangs in small aquariums; they don’t buy fish that get very large unless they have the properly sized marine system; they acquire fish according to their ability to properly house them; and they acquire a fish for life, not just until it grows to an inconvenient size. See: Thrive, and Marine hobbyist

Marine hobbyist - The person who, as it relates to marine systems, could be just starting out, or reached a limited level of marine life care. The person may be on their way to becoming a marine aquarist, or they may just consider marine husbandry as a hobby. These people are into or getting into the setup and controlling the system, but may lack knowledge, experience, and a ‘correct’ general understanding the basics of what is going on inside their marine system as far as science and research has proven. Their water quality is sometimes off or drifts outside of the normal parameters. Their specimens are fed with what is easy to feed, rather than understanding and providing the marine life forms with their nutritional needs. Hobbyists sometimes loose specimens from lack of understanding of what has to be planned for and what a particular lifeform needs to survive. Too often they listen to people who are other hobbyists with wrong ideas, rumors, or lack marine husbandry knowledge (sometimes out of not knowing whom to trust). Marine life in their care are sometimes or often in the surviving mode, rather than a thriving mode. Lastly, the experienced and knowledgeable hobbyist is still a hobbyist if they do harm to marine life and/or acquire marine life unsuitable for their marine system. See Survive, Thrive, Marine aquarist.

Marine system - More than just the marine display tank, this includes all the places the water goes and lighting. The system includes tank, sump, refugium, skimmer, filters, chiller, UV, generators (e.g., Calcium), ozone makers, the plumbing, lighting, heater, etc.

Mature marine aquarium (system) - The marine system reaches an age when it has (for the most part) chemically and biologically stabilized. Water quality through routine maintenance, attention to details, etc. is kept more or less constant and excellent; nuisance microbial and algae growths can no longer thrive; waste nutrients are under control AND reduced to a minimum; and the aquarium is suitable for sensitive marine life forms. This maturing process can take 6 to 8 months, or more, or less, depending upon several factors. See: The Mature Aquarium

Mechanical filter - These filters act to remove particulate matter from the water in the marine system, including detritus when system circulation is high. They include canister filters, filter socks, filter floss, etc. Anything that captures solids and removes them from the water. Such filters can be problematic if not kept clean. Socks for instance, should be changed out/cleaned every two days the most or more frequently in a crowded fish marine system. A dirty filter accumulates detritus and wastes that are still adding nitrogen wastes into the marine system which may lead to water quality problems. Some such filters will accumulate nitrification bacteria and contribute to the biological filter. Some designs of these filters separate solid wastes (filter material) from the media that holds the nitrification bacteria.

Media - A broad term used by marine aquarists to describe a purposefully placed solid material into the marine system. It includes things like substrates, absorbents, resins, filter material, etc. Examples include but aren’t limited to: activated carbon, sand, bio-balls, resins that absorb wastes/pollutants, etc.

Mesh - Used to describe particle sizes. For instance, a mesh of 10 is 2000 microns (2 mm); 20 is 840 microns (approximately 1/32 if an inch); a mesh of 40 is 420 microns (about the size of a baby brine shrimp). A mesh of 70 is about a 210 micron sized particle. See Micron.

Micron - Technically this is one millionth of a meter. Most hobbyists and aquarists know what a baby brine shrimp looks like. That particular size is approximately 450 microns. This should give the reader some idea of the size of a micron. A 200 micron filter would hold back particles larger than 200 microns (or about half the size of a baby brine shrimp).

Nitrification - Used to describe the action of a typical biological filter. The chemical reaction done by bacteria converts ammonia waste to nitrites and then nitrites to nitrates.

Nitrogen cycle -In the broadest sense of the term to marine aquarists, this is the combination of the nitrification process and the denitrification process of all nitrogen wastes. That is, this term represents the chemical process that takes waste nitrogen products (such as in proteins) and changes some of it to ammonia, then changes the ammonia to nitrite, then changes nitrites to nitrates, then changes nitrates to nitrogen gas and other chemicals.

Nitrogen wastes - Most (solid) wastes in the marine aquarium contain nitrogen. They include ammonia, proteins, certain lipids and fats, ‘organics,’ and amino acids to name a few. They come from things the aquarist puts into the system such a foods, vitamins, and fats, as well as things made in the marine system by marine fish, marine lifeforms, bacteria and other microbial organisms, such as proteins, toxins, ammonia wastes, etc.

Nutrients - Generally used to describe all the things needed by an organism to thrive.

Omnivore - Marine life (fish in this case) that eats both animal and plant proteins. These fishes have the greatest choices of foods and are Nature’s favorites in that they have a lot of foods to choose from.

Osmoregulation - This is the word used to describe how the fish controls the amount of salt it has in its body. The environment the fish is in is high in salt content. The marine fish needs to obtain fresh (non-salted water) to carry out internal biological functions. The fish drinks salt water, removes the salt, and sends the salt back into its environment. The fish internal system controls the amount of salt inside the fish. This control is known as osmoregulation and it takes quite a bit of the fish’s energy.

Piping - Describes a fish that goes to the surface to gulp air. Either the oxygen content of the water is too low, or the fish is having gill problems so that it can’t get enough oxygen into its system. This is of course excluding fishes with lungs that do this normally.

Powerhead - See Circulating pump.

Refugium - The part of the marine system where the aquarist has set up to contain marine lifeforms that wouldn’t survive in the display tank. This is often another tank in the marine system where macro algae, a deep sand bed, mud, and/or other marine organisms are cultured or maintained.

Return pump - This is the pump that take water from the sump and returns it to the display tank. It keeps the water going back to the display and overflowing into the sump. The flow rate of the return pump can be easily misunderstood. The pump is rated for a specific flow at a specific head pressure. That flow must be adjusted up or down depending upon the head pressure.

Setup - Sometimes used instead of marine system. As a verb, it would mean the establishing of a marine system. A single common error made by hobbyists would be to try and put the setup together a piece at a time. For the sake of achieving stability and maturity as soon as possible, the assembly of the marine system should be complete at the outset. Adding bits of live rock to a system (as it can be afforded) is not advisable, for instance. Save money until there is enough to buy everything needed to set up a complete system from the start. See Marine system.

Shy fish - I classify most marine fishes into one of three groups relative to how they act in captivity. The three groups are Aggressive fish, Assertive fish, and Shy fish. They are defined by 3 main responses. This fish doesn’t like to swim in the open and will usually retreat completely hidden or just able to watch from a total safe/secure place. It may come forward to greet the feeder after familiarity is well established and depending upon its tank mates. During feeding, this fish usually hangs on the fringe of the community group that is eating at where the food drops in. If the hobbyist/aquarist puts a gloved hand or equipment into the aquarium, this fish will be totally out of sight even before anything enters the aquarium.

Specific gravity - The ratio of the density of the sample liquid to the density of pure water. This measurement has no temperature correction to it, so it is not the most accurate means of measuring the salt content of aquarium water. For more technical information see: Specific Gravity

Sump - In the designing of a marine system, a sump holds water coming to it by gravity from the display tank overflow(s). The sump may have inside of it several pieces of equipment to make more room for lifeforms in the display tank. Such things that may be found/put inside the sump include a skimmer, heater, chiller, mechanical filter, biological filter, etc. Water in the sump is pumped back into the display tank where it forces more water into the overflow(s) sending more water back to the sump. This cycle continues in this manner unless/until the return pump stops. Then all the excess display water goes into the overflow and then into the sump. The volume of the sump must comfortably hold this volume of water, plus any volume displaced by the equipment put into it.

Survive - The marine life form that barely holds onto to life from what the hobbyist or aquarist is providing is said to be surviving. See: Thrive.

Tank hopping - Moving a fish from a display tank to a larger display tank when that fish gets too large for the tank it is in. Many marine fishes can be kept in small aquariums then, when they outgrow the tank, can be moved to a larger one. But some fishes, like Large (adult) Angels, Tangs, and Rabbittfishes for instance need a large swimming space right from the time they are acquired and would be stressed in a tank that to humans, would seem a large enough space or length. Thus these fishes should not acquired with the intent to 'later' put into a larger tank.

Thrive - When a marine fish or lifeforms has all the nutrients it needs, is growing, healthy and its sexual organs are maturing at the proper rate, the fish is living to its fullest potential with a minimum of stress. This word is used to describe this state of animal husbandry. See: Survive.