I am new to the hobby and have really been enjoying it. My fish seem happy and striving but I want to do things the right way at least as much as possible. I use the API test kit. My ammonia is very near 0 and my nitrate is approx 10 ppm. Ph is 6.8. Problem is the nitrites are what seems to be through the roof. Like nearing 5ppm. I do partial WC(25-50%) every other day and it doesn't really seem to bring the nitrites down. Any suggestions?