I agree get him out as quickly as you can into a QT tank. Some people may not agree with me but I used Pemafix & Melafix when my Yellow Tang top fin started to disappaear to nothing but the spikes sticking up and it grew back to my supprise and he also got a cut on his side and it also healed that up as well... But the Pemafix & Melafix has not helped my Desjardin Tang with the HLLE
diease which I am still today trying to find out what else I can use to help him heal. If you have a Walmart in your area and a spare $70 to I think $80 go and get the 20 Gal
Start up tank and make it your QT I don't think it is much more then that. I have read that all you need in the QT tanks is a piece of PVC
pipe or a small clay flower pot for the fish to sleep in at night a basic power head for a 20 gal
tank and of course your saltwater and your medication. Do not use any carbon filters when treating your fish. And I just this tank online at www.petsmart.com
Top Fin® Aquarium Starter Kit - 15 Gallon
at Petsmart for $71.99 it says in-store only.