What are your tank parameters? Knowing what levels certain nutrients are can help ( eg; nitrogen, ammonia, phosphate) etc.
Also how long are your lights on? Too many nutrients and too much light can certainly cause problems. When it doubt, do a good sizewater change and do a water test. Post here, and we can help more.
75 Gallon Saltwater Reef
Just your average LVT (licenced vet tech) trying to help the world's animals!!