I agree....quarantining doesn't always mean medicating. You just want to QT him for a couple weeks to make sure he doesn't have any diseases or parasites that would make your other fish sick. Keep an eye on him and do water changes often (atleast once a week) in the QT tank and if all is well in a couple weeks, move him to the main tank. Make sure you have a heater and filter on the QT tank.

If he shows signs of a disease, then you'll want to medicate, but cross that bridge when you get there.