Check for a micro bubble leak in your filter, maybe your filter or one of your pumps is the culprit.

Also, did you use tap water when you started your tank?
You could have a nitrate or phosphate problem.

Also make sure you have good water flow all around your live rock and try to keep all your live rock at least 4 inches away from any glass walls.

Good luck, just getting over the same problem myself.



Ps. Set your timer so that the lights are on with a two hour break in the middle of the day cycle. This helps with algae growth since algae needs extended periods of light to grow.