Ow. It probably will make it, but run carbon, run fresh carbon, and a lot of it in several women's kneehigh nylons. I don't personally know this product, but never let anybody talk you into putting anything into the reef tank that is designed for fish---and read the label three times before you add anything designed for corals. You have two choices: take the coral out or take the fish out, and I would recommend the latter, earnestly. Renew the fish treatment in a cheap barebottom tank. Treating your fish in a display tank may get medication or metal poisoning into corals, live rock, live sand, and your filters if any. On the other hand, look at the other corals, and judge for yourself, based on how many days more this treatment has to run.
The only mostly reef-safe treatment I know of is Maracyn, and Chemi-clean, which I suspect of being Marycyn, at least in part, and even those slam the surface of the active sand bed pretty hard. [I think if you have a truly dsb it will recover, but either it or the cyano it's designed to treat it lowers the pods drastically, and a sandbed crisis will provoke a nitrate rise and algae bloom if your sandbed biosystem absolutely is killed off.] At any rate---what you added may have been Maracyn, is my point. Or it may not have been. But carbon preceded by a major water change, at least 20%, are a good idea here, IMHO, when something odd is in your water. If you don't see improvement in that specimen, I'd go on with the carbon and daily water changes.
Here's the gist of it: fish ailments are caused by a) bacteria or b) parasites. We don't deal with viruses, nor could. Bacteria are treated by an antibiotic. Parasites are treated by a poison, or by hyposalinity which causes their complex cells to implode or explode, one or the other.
And here's the catch: antibiotics don't care what bacteria they kill and your sandbed and live rock are live because of...bacteria.
Poisons will hopefully kill the tiny parasite organisms (which live fast) before they kill the fish, which have slower metabolism. They will, however, kill every invert and much of your bacteria, and persist in the rock and sand, so that it has to be discarded, along with the tank itself.
Hypo again is based on the theory the parasite will die before the fish does.
HTH.
