More info on your tank setup would help...
Having said that, I think water changes are the easiest way, but the best thing to do would be to find the source of this nitrate problem. Has your nitrates gone up just recently or has this been an ongoing problem? You may want to review your bioload. Too many fish? Overfeeding? Any animals gone missing recently that may be dead behind your rockwork? Have you checked your skimmer to make sure it's working properly? How's your water quality besides the nitrates?
__________________
-Mason
|