You mix your salt before you mix your saltwater yes? I've found with Red Sea you have to mix your salt in the bag. Just take it out of the bucket, and hold the bag end really tight and upend it about 20-30 times.
Also Was the torch every happy and healthy in that spot in this tank?
While generally you can use a single coral as a tank indicator, if the rest of everything in your tank is doing fine, it's not smart to change entire tank conditions for a single coral.
If other corals are looking less bright, less extended though then there's an overall problem.