Thanks again everyone for all the help, and kind words. I've left the tank alone other than skimmer cup cleaning and changing out filter socks. I noticed some polyp extension today on the troubled corals. The ICP lab test went in the mail yesterday. I'll update as soon as I see results. And will continue to keep you all posted.
Side question. If it is chlorine or chloramines, would it hurt anything to add prime to my water change water? It says it removes or detoxifies chlorine and chloramines so the biological filter can filter it out. Is this something I should just include in my routine maintenence? I'll obviously wait until the results come back, but just wanted to throw it out there.
Just an FYI, if you do add prime, and then start doing any ammonia tests, you can get false positives.
See FAQ at
Seachem - Prime
seachem.com