A couple months ago I was in the middle of transitioning a fish only aquarium to a reef when my tank broke out with ick. Since all we had was live rock we removed it and treated the main tank with copper. I am wondering when I can start adding my live rock back into the main tank.
Probably never, its probably into the silicone and leechiing back into the system. Get yourself a copper test before you add any of it back into the system. Copper should always be used in a quaranteen tank.
If there was anything but a bare, empty tank, you really can't reuse it. You took the rock out, which is good, but if you had any substrate (sand, crushed coral), that is trashed now.
Unless you change out 100% of the water, your live rock will turn into dead rock. If you want to transition to a reef tank, I would suggest emptying the tank, give it a good scrubbing, then starting all over again .