Update:
Did another very large water change yesterday >150 gallons. A few colonies are now completely gone, such as the WWC yellow tip, ATL Bloody Mary, Pro Corals Rainbow, UC Unknown, CB Thing, ice fire, pomade bird, and a few other non-named pieces.
The rest still have some skin or polyps, but I can't imagine they will make it. I snapped some pics while the tank was empty.
This tort has been growing for three years and started with a 1/4" nub.
Blue tipped tenious
Mystic sunset:
Top down FTS:
Most of the rest of the SPS have at least 1/2" of flesh. We'll see how they do over time. LPS and zoas all seem to be fine, including all of the favia. Only the acan appears to be a bit deflated.
Only fish that remain are purple tang (visibly sick), mimic tang (dying any day), Blond Naso (seems completely unaffected), two of the nine lyre tail anthias, midnight blenny and black Cardinal. Everything else is gone.
Thanks again to everyone for the words of encouragement and offers for new frags. You are a great club and I'm glad to have your support. It's those words of encouragement that convinced me to stay in the hobby.