Open brain pulling away from skeleton

My water params are all normal except phos was at .25 3 days ago

This is in my 70 gal. I did a 10 gal wc yesterday, and this brought phos down to 0

Should I do another wc? Dip him?

My other brain is fine as are all other corals except a goniopora that's no longer extending(been this way for 2weeks)

 

If you're looking at those areas with a lack of color around the edges, those just look like the underside of the tissue to me. Looks like it's exchanging water and slightly pulled in. I don't see any skeleton.

 

ITs never been that way before, but thats normal?

 

As long as it puffs back up again within a day or so, yes.

 

Looks like it is showing skeleton,

It's getting worse this am.

Any suggestions on what to do?