So your topoff is 1 gallon per day?
Great, mix that up to 1.030 SG
and use that for your top off till the tank slowly comes back up to 1.025.
Fish do quite well at 1.020, corals need it higher (as you found out).
How did you calibrate your refractometer? Did you use a solution or DI
I generally do both and check it quarterly.