Donut Coral Strange White Tissue

[Soukadesu]

Hi Everyone.
A few weeks a go I saw a white tissue underneath colored tissue on my donut coral. It seems the two are not blending just like 2 layers but strangely on the edge it's still connected. Suddenly 1 week a go I notice the white tissue is mostly gone and replaced with white skeleton. Some of the white tissue is there though.
Could anyone give advice what the white tissue is and how I should approach from now?
I've been broadcasting feed reef energy ab+ daily and the only change is that I use narrow reflector for my kessil. Sometimes every 2 days I substitute with direct feeding of reef energy. Other corals seems fine. My nitrate is around 10-20 and I have 2 other donut coral beside this.

 

[vetteguy53081]

Tissue recession and can be caused by:
Inadequate light, water flow or both
Salinity too low
Sand irritating it
High alk
Low calcium
Low ph
High temperatures
Nitrate or phosphate High

 

[Soukadesu]

Tissue recession and can be caused by:
Inadequate light, water flow or both
Salinity too low
Sand irritating it
High alk
Low calcium
Low ph
High temperatures
Nitrate or phosphate High

Salinity is 33 ppt using aquaforest reef salt. Previously using the AF Reef salt.
No sand. Bare bottom. The donut coral is hoisted on some plastic cup a few centimetres above the glass bottom.
Temperature stable 25-26

Is 10-20 nitrate high? Probably phosphate 0.25. It's hard to read the color on the test kit.
Other corals are fine and opening especially the other donuts.

What is the white tissue which recessed later on? It was a fat white tissue.

 

[vetteguy53081]

Salinity is 33 ppt using aquaforest reef salt. Previously using the AF Reef salt.
No sand. Bare bottom. The donut coral is hoisted on some plastic cup a few centimetres above the glass bottom.
Temperature stable 25-26

Is 10-20 nitrate high? Probably phosphate 0.25. It's hard to read the color on the test kit.
Other corals are fine and opening especially the other donuts.

What is the white tissue which recessed later on? It was a fat white tissue.

I looked this up on my regular computer screen
That’s not recession but rather sponge
You will need to trim away and so so outside of tank in a container of tank water
Exposing it to air will help
Other option is to inject vinegar into it with a syringe

 

[Soukadesu]

I looked this up on my regular computer screen
That’s not recession but rather sponge
You will need to trim away and so so outside of tank in a container of tank water
Exposing it to air will help
Other option is to inject vinegar into it with a syringe

That explains it. Near it there is a sponge attached to a rock. Far but perhaps spore from flow. It really looks like meat but then again I recall it also looks like the nearby sponge. Many thanks you save my day.

 

[SaltyReefer09]

Hey man
Any update on ur donut coral?
im having the same issue with mine. And its exactly the same colour as yours.
and im also using AF reef salt.
Would love to know if yours got any better and how did u treat it.
thanks