Zoas regressing

[dugthefish]

Started off as a frag with maybe a dozen polyps, in the last 6 months its grown quite a bit. This last week many polyps haven't been opening, frags on the other side of the tank are fine. Any ideas? All water parameters, flow, and lighting have remained consistent for the last couple months.

 

[Robert_ellis]

Looks like something is growing inbetween the zoas. Some white stringy stuff. Probably irritating the zoas.

 

[dugthefish]

Looks like something is growing inbetween the zoas. Some white stringy stuff. Probably irritating the zoas.

I was wondering if that could be it. Not sure what that is, some sort of non photosynthetic hair algae? I have that in several areas of the tank, this seems to be the only spot that ita causing issues....

 

[bassrock234]

I was wondering if that could be it. Not sure what that is, some sort of non photosynthetic hair algae? I have that in several areas of the tank, this seems to be the only spot that ita causing issues....

They are definitely being irritated.
I would take a light bristle toothbrush and brush in between them softly and see if it let's go.
Good luck!