How many QT new or sick fish for ich?

[Lance]

I have a 20 gal QT tank that stays up and running with substrate, live rock and a skimmer. All livestock goes in here except for the occasional coral that I get from a reliable source. Fish stay in QT for at least 2 weeks. If they're eating well and looking healthy after 2 weeks, into the DT they go. If they develop a problem I have a 10 gal treatment tank I set up.