I would offer the advice of ALWAYS doing a quaranteen tank, especially with Angels and Tangs.
I always end up yanking ALL of my live rock to chase down a ICH-RIDDEN fish.
Everytime I've been too excited to see new livestock in my display tank. Everytime I've introduced parasites into my tank.
My advice is: "Consider buying/setting up a QT BEFORE you buy any new fish." And, use the damn thing.
Hyposalinity works and does not introduce your fish to harsh conditions.
On the brightside, I've gotten pretty good at re-aquascaping after tearing everything down to catch a fish.