I would recommend you go to one of the reef forums. The local one
http://www.tcmas.org/v4/forums/forum.php?tabid=11or reef central
http://www.reefcentral.com/Some one may chime in here but check these out especially if your salt water hobbyist.
My recommendations taken from a reliable web site · Treatment of the affected fish usually involves some or all of the following procedures:
· Freshwater dips dosed with methylene blue plus formalin
· Lowering specific gravity (hyposalinity = 1.010-1.013) of the quarantine tank
· Continuous exposure for at least 28 days to 0.15 to 0.20 ppm copper, although copper in and of itself can have long-term negative effects/only in a quarantine tank no copper in display if you have corals and/or inverts
· Antibiotic feeding (preventative against secondary infection)
Set up a quarantine tank simple 10g or 20g for future purchases.