It's only affecting these two corals so far, an acan and a trachyphyllia, and both started at about the same time in the last ~24 hours. The stuff on the Trachy blows off with a powerhead. So far no flesh damage on either that I see, but I'm hoping to avoid that.
It's definitely white, but the filter gives it some color.
I don't dose carbon or anything, and I'm not currently running carbon/GFO. I do have purigen.
I'll post test results on everything as an edit/update
