Dont combine IMHO. wait/watch. @Jay Hemdal will weigh in. Dont jeopardize the rest of your fish for 1. IMHO - this looks like severe / significant lymphocystis. How is the fish doing otherwise?
The fish seems fine. I tried to give a brief freshwater dip and attempted to see if these sacs come off easily. That stressed the fish out, but it was fine shortly after this. No heavy breathing. The fish is eating too