I assume you started a thread about it. If so, I don't remember the specifics of your tank set up and problem. Have you figured out what is causing them? Heavy feedings, overstocking, dirty mechanical filters or media, ...? You must eliminate the source to fix the problem. Generally frequent, large PWC
's w/ NO3
free water are good for reducing NO3
. When doing that it is even more important that you match the parameters of the new water to that of the tank.