0 Nitrates?

[sappho]

I added seachem denitrate to my 55g in the hope that maybe it would help keep nitrates low but after a day and a half my nitrates went from 20ppm to 0? I read about many people using it and lowering their nitrates over time but this seems too good to be true. Is it possible that Im getting a false negative? My fish all seem happy and healthy. If the denitrate is working, do I still have to do water changes? and how often?

[bertoni]

I don't think the DeNitrate did anything for your system in that time frame. I would still do water changes on a regular basis. They will help keep the ionic balance in good shape:

http://reefkeeping.com/issues/2005-10/rhf/index.php

I don't know why the level dropped, but I doubt that it's a false negative.