My Nitrates As for MY nitrate problem in my freshwater tank, I think it is due to the fact I had a powerhead AND a filter working and it's only a 10 gallon. The bacteria that kills nitrates doesn't like oxygen rich water. I did almost a 50% water change last night and today the nitrates were still high so I unplugged the extra powerhead, added a nitrate remover pebble bag, and will do another small 1 gallon WC just to lessen the cloudiness from the pebble bag. I just need to worry about my 75g now, because of all the hard-to-reach dead spots. Even if I get another powerhead to fix these spots, I need to clean them up first, and THAT'S what I am afraid of doing. Talk about cloudy water!!!