Green Slimmer bleaching.

[ChiTown81]

My green slimmer coral has been turning white this past week. I had it originally towards the top of my tank, my levels have been:
SG- 1.023
AK- 8.3
CA- 477
I have 2 blue damsel fish so I’m not sure if it’s my levels or it got too much light.

 

[Hydrored]

That is tissue necrosis

What is your age of tank? Lighting? Flow? Phosphates? Nitrates? What are you dosing to the tank and what media if any is being used?