Should I be concerned about my brain coral?

[bigearsnyc]

I added this coral to my tank about 4 months ago. There was a little bit of black on the far left head. It seems like it is getting bigger.

Is this a problem for the coral? Overall the coral seems to be healthy - it will extend its tentacles to filter for food. This happens mostly on the far right head.

My water parameters are pretty consistent. I can post more details for my tank if needed to troubleshoot.

Thank you

 

[bigearsnyc]

Here is a picture.

 

[Finland]

Looks like it is receding. Keep things stable and it should recover. You may get some better responses if you post this in the LPS forum.