Thanks for answering- I just did a 50% water change (nitrates at 10 ppm before the water change) This is a planted tank and 11 days ago I added three Flourish Tabs to the gravel. They are all still covered up, (although the gravel is only about 2 inches deep), I've never used these before, do you think that is what is causing it? (no one has been here for the last couple days to add anything I wouldn't know about, like a penny or something)
