How long in treatment tank?

[Reefy Feller]

I have a yellow tang that had a spot on his right fin. Caught it early, only had the one spot and no other fish in the DT seem to be effected. I've had the tang in treatment tank with coppersafe for about 18 days now and spot is gone from his fin - he's cruising around the tank normally, has good appetite. How long should I keep him in the treatment tank for before returning him to the normal tank?

 

[Spare time]

Typically 4 to 5 weeks is the safest. Average marine ich cycle is two weeks, most by 3, and a few that can go longer (4 or 5 weeks). Typically 4 weeks after it appears gone off the fish would be considered safe.