I was having the same problem.......turns out the tank was getting way too much light. I had about 12 hours of my daylight bulbs per day. I've moved my tank out of any sunlight and cut back the hours of my lighting. My actinics come on at 8:00am, the daylights come on at 10:00am and go off at 6:00 pm and my actinics go off at 8:00pm and my lunars are on for the rest of the time. I also have some great water flow in there and things seem to by doing well.