Originally Posted by
GeoJ
This is not so, a properly functioning system will zero out.
Nitrate is not the end of the Nitrogen cycle
Ammonification
Nitrates are the form of nitrogen most commonly assimilated by plant species, which, in turn are consumed by heterotrophs for use in compounds such as amino and nucleic acids. The remains of heterotrophs will then be decomposed into nutrient-rich organic material. Bacteria or in some cases, fungi, will convert the nitrates within the remains back into ammonia..
Nitrification
Main article: Nitrification
The conversion of ammonia to nitrates is performed primarily by soil-living bacteria and other nitrifying bacteria. The primary stage of nitrification, the oxidation of ammonia (NH3) is performed by bacteria such as the Nitrosomonas species, which converts ammonia to nitrites (NO2-). Other bacterial species, such as the Nitrobacter, are responsible for the oxidation of the nitrites into nitrates (NO3-) (Smil, 2000)
Anaerobic Ammonium Oxidation
Main article: Anammox
In this biological process, nitrite and ammonium are converted directly into dinitrogen gas. This process makes up a major proportion of dinitrogen conversion in the oceans.
Denitrification
Main article: Denitrification
Denitrification is the reduction of nitrates back into the largely inert nitrogen gas (N2), completing the nitrogen cycle. This process is performed by bacterial species such as the Pseudomonas and Clostridium. (Smil, 2000) .
You see that a little Anaerobic water can go a long way to keep the tank clean, but if not kept in checked hydrogen sulfide producers can be a prob!
so keep the water moving and the sand sifting
add more rock and sand if you dont zero out
your information is great. though I noticed no mention of nitrospira bacteria wich is actually more common in home aquariums, nitrosomonas and nitro bacter are just the bacteria that labrotories use because they are the easiest to grow in a lab setting so the resulting data is minorly skewed. I agree that with available anaerobic zones or proper macro algae you can run a nitrate free tank, mine is. but not all hobbiest have their tank set up in this way.
Great information though.