Bubble coral receding

[starfishguy869]

Hello all,

I was cleaning my tank and decided to move a bubble coral as it was touching the glass. However, when I did a little inspection on it, I saw that a part of flesh has disappeared. I have attached a photo below. The coral looks healthy and happy. If anyone could help me, it would be greatly appreciated.

 

[vetteguy53081]

Hello all,

I was cleaning my tank and decided to move a bubble coral as it was touching the glass. However, when I did a little inspection on it, I saw that a part of flesh has disappeared. I have attached a photo below. The coral looks healthy and happy. If anyone could help me, it would be greatly appreciated.

Assure flow not aggressive and alk not elevated or calcium low

 

[Shirak]

Can't see anything with the blue light. White light for pictures please!
Water parameters?