Peter Pan wrote:
Denitrification (low oxygen) reduces nitrates.

Thanks Wayne, can you explain Denitrification for me? Does this mean
adding macro algea?
The end result is I would like to reduce my nitrates. I keep them under
15pmm via 1/3 water changes each month. I was hoping there was a way I
could do even less and get the same results



Read up on the nitrogen cycle:
http://faq.thekrib.com/begin-cycling.html

Denitrification occurs with bacteria in the absence of oxygen. Oxygen
starved bacteria pull the oxygen off of nitrate and release nitrogen gas
which out-gases from the water. This bacteria lives in deep sand beds
and in crevices of live rock.

--Kurt