Quote Originally Posted by JimD View Post
Need more info on the tank, ie: flow, feeding, lighting, FLOW, sandbed, refugium, FLOW, fish, skimmer, water for changes, did I mention FLOW?
I agree with the above but, usually the problem is over feeding, or using water with too much phosphates, etc. Use only RO/DI water and stop feeding a few days or, cut the feeding way back might help.