Hello all! I'm trying to figure out what are appropriate levels for ammonia, nitrite, and nitrate in a tank and what could cause rises in these levels. I've had my tank for at least three months now. I tested the water today and the ph is 6.8, ammonia 0.5, nitrite 0, and nitrate 10. I've read that as long as your nitrate is under 40, that's good, but ammonia and nitrite should be 0. What could be causing my high ammonia levels but nitrite levels are fine? Thanks in advance!