I don't share everyone else's point of view on the issue of QT
tanks. I don't believe they are necessary unless you have some livestock that you want to proctect at absolutely all costs. QT
tanks are very stressful on fish as they are usually too small and have poor water quality. I don't want to start a debate about it, but that's just my feeling.
I agree with everyone that you should leave your tank empty (of fish) for at least 6 weeks. Lowering your salinity to 1.018 or 1.019 and raising your temperature to 82 degrees would also help as it speeds up the life cycle of the parasite (causing it to die off faster without hosts).
Finally, when you are ready to add a fish, I would highly recommend that you do not add a tang. They are very suseptible to ich. I would recommend something much more hardy, like a clown.
92-gallon corner tank, 100lbs of LR
, 140lbs of sand, 250watt 10,000K MH
, 110watts of actinic PCs, Mag 7 return, custom refugium, AquaC EV180 w/ Mag 5
Female lyretail anthias, eyelash blenny, tomato clown, saddleback clown, firefish goby, 2 sand-sifting stars