How Long should I treat Ich?

[Nano]

I have as some of you may know, a Ocellaris, that had/has ich, I have been treating him for 2 weeks come saturday, first with ich attck and now with.. I cant remember the name I got it from red coral edmonton. anyways he hasn't had an outbreak since saturday, I'm wondering if this saturday or sunday is too soon to stop treating and add a fish? or should I wait? or could I add a fish and continue treating the tank to take care of any possible ich the new fish could be carrying as well?