Results for “nitrates”

nitrates

Any salt or ester of nitric acid, and the end product of the portion of the nitrogen cycle taking place in most closed aquarium systems (the conversion of nitrates to nitrogen gas in natural systems is carried out by anaerobic microorganisms not normally present in sufficient numbers in aquaria, though this process can be induced by installation of a nitrate reactor). While nitrates are less toxic than ammonia or nitrites, they are still potentially harmful to fishes and other aquatic organisms if allowed to accumulate unchecked, and must therefore be diluted via regular water changes. Aquatic plants also help since they are able to metabolise nitrates to an extent.

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nitrate reactor

Piece of aquarium equipment that can be thought of as an anaerobic filter. Provides a means by which large enough populations of anaerobic bacteria can be maintained so that nitrates are actively removed from the water in the form of nitrogen gas, a process normally facilitated by regular partial water changes. Also known as a nitrogen filter.

denitrification

Reduction of nitrates to nitrites and ammonia by the breakdown of nitrogenous compounds, or conversion of nitrates into nitrogen-containing gases. Usually carried out by microorganisms.

activated carbon

Processed, porous, highly adsorptive form of carbon also known as activated charcoal or active carbon. Used in aquaria to remove toxins such as chlorine, chloramine, some heavy metals, and especially organic molecules, but exerts no action on ammonia, nitrite, nitrate, phosphate or inorganic salts. Since it has a finite surface area it requires periodic replacement if employed long-term, and should be removed if a tank is being treated as it will remove most medications. Cannot be 'recharged' by heating in a microwave or domestic oven.

deep sand bed

Method of filtration, mostly used in marine aquaria, whereby the increased depth of the sand substrate facilitates formation of an anaerobic layer where nitrate can be converted into nitrogen gas. Also known as "Jaubert" or "plenum" system and often associated with live sand.

denitrify

To reduce nitrates to nitrites and ammonia by the breakdown of nitrogenous compounds, or convert such compounds into nitrogen-containing gases.

eutrophication

Hypertrophication; process by which addition of artificial or natural substances, such as nitrates and phosphates, to a body of water increases the concentration of dissolved nutrients, this in turn stimulating the growth of aquatic plant life, especially phytoplankton, and typically resulting in depletion of dissolved oxygen. Negative effects include reductions in populations of fishes and other organisms incapable of withstanding this hypoxia.

Used in 8 profiles

nitrify

To convert ammonia or other nitrogen compounds into nitrites or nitrates.

nitrites

A salt or ester of nitrous acid. Produced in aquaria via metabolisation of ammonia by nitrifying bacteria of the genus Nitrosomonas, and toxic to fishes if present in sufficient concentrations, but in a mature system is further converted into less-harmful nitrates by other bacteria of the genus Nitrospira.

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Nitrobacter

Genus of bacteria previously thought to reduce nitrIte to nitrAte in an aquarium, but which does not occur, or occurs in negligible quantities, in aquaria.

Nitrospira

Genus of bacteria which reduces nitrIte to nitrAte in an aquarium.

wet/dry filter

Type of filter normally placed under the aquarium, and often home-made. The basic premise is that water trickles vertically downards through separated compartments containing mechanical and biological filter media with spaces inbetween so that it is also exposed to the air briefly. It then collects in a base chamber or sump from where it is pumped back to the main aquarium. There are many commercial designs available, some of which are more effective than others. Not popular in marine reef aquaria due to the associated accumulation of nitrates as by-product.