Peter Pan wrote:
to help reduce your Nitrates, you need to do more frequent partial water
changes. This will reduce your levels quick and wont be harmful to the tank.
Try and do 10 - 15% per week for about a month.

Well, it won't really be quick. It would take 7 partial water changes of 10% to
cut the nitrates in half. If no nitrates are generated in the meantime. Kick it
up to about 25% if you can. Three 25% changes will bring it well below the
halfway mark.

George Patterson
Forgive your enemies. But always remember who they are.