I wish this was included in more beginner FYI's or on the salt mix instructions. I don't know how many gallons I mixed before I realized my numbers were off because I didn't mix the dry salt in the salt bucket first. (Also using Instant Ocean).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.