So i haven't quarantine the other fish. I wasn't sure if they got ich from the cowfish and was worried to quarantine them with cupramine when they could have been healthy. Now, one of my clown fish has ich maybe. I just put in a new power head and I am not sure if he has sand stuck on him or he has ich. If this is ich I will definetly quarantine all my fish
I would properly quarantine all the fish and let your system go fallow for 76 days. Which exact fish brought it in is anybody's guess, and not relevant at this point.