I was looking at my reef today and realized this favia looked like it had come sand on it, I suspected maybe my fish spit some sand on to it. I was blasting it off and realized the actual flesh starting coming off. There have been no light changes or flow changes. I’ve had it for 2 months already and never showed any signs of stress. All other corals are doing well. Any idea what could cause this and how to save it?
Nitrates <12
Phos .06
Calc 440
Mag 1380
Alk 11
Nitrates <12
Phos .06
Calc 440
Mag 1380
Alk 11