Nitrate is primarily introduced into a frag tank by fish consuming food which you have fed them, and converting it into ammonia – the first part of the nitrogen cycle.
The tendency to keep only a few fish in a frag tank often leads to a deficiency in nitrate. To counteract the deficiency we are often temped to feed more. The problem is that this increase will also contribute to climb in phosphate.
How do we ensure that nitrate is maintained at a level suitable for your frags?
Without raising phosphate, reef keepers often begin dosing nitrate. This is in the form of Potassium Nitrate, or Sodium Nitrate.
Most frag tanks do not suffer from high nitrate, and for that reason we don’t often need to consider excessive nitrate control.
Unfortunately a protein skimmer in a frag tank will be indiscriminate. Skimmers are very efficient at removing the potential for nitrates in your system, by removing any waterborne fish excrement or detritus.