Nitrates at 40

[GaryP]

Denitrification is accomplished by Pseudomonas bacteria and others. This process is anaerobic, occurring in the absence of oxygen. Obviously, denitrifying bacteria cannot live on the oxygenated surfaces on which nitrifying bacteria live. The only places where denitrifying bacteria are found are where there is a source of nitrate but no source of oxygen. In an aquarium, anaerobic activity is most likely to occur in a deep layer of gravel or sand with no water flowing through it. Anaerobic activity can also take place in a clogged filter, where nitrate is available but water is moving so slowly that it loses its oxygen before it travels through the filter.

[JimD]

Turn your wet-dry into a refugium and kiss your nitrates goodbye. Also, make sure you have plenty of flow, no dead areas for detritus to collect and decay, periodicly use a turkey baster to aggitate any detritus from the rock surface and caverns immidiately before a water change. Do regular maintenance on any filter socks you may be using,, etc. etc.....