Paul is on the right track, I had off the wall nitrates for months after using all dry rock and having only 2 fish. It just takes longer for the nitrate bacteria to get a foot hold. As I previously stated I ended up using vodka after a few months, but now( about 10 months later a was able to wean it off vodka and my nitrates are below 5 at least for now. Things just take time sometimes .



