So awhile ago my black moor goldfish got a fungus so I started using MarineLand All-In-One-Remedy. I used the whole bottle even when I saw the fungus appeared to be gone. Well I completely cleaned the tank and everything in it. Then a week later it came back and it almost covered his eyes. I had to finger feed him his flakes. Anyway I got another bottle and treated until it was gone again. I gave everything another cleaning and gave everything a peroxide bath, and changed his gravel. Then it came back AGAIN. Well this time it isn't to bad its in smallish patches and on his mouth. But it looks different, not so much fuzz like it was but more like white peach fuzz almost almost unnoticeable. So I went to my pet smart and asked what was the deal, what I was doing wrong etc. They said it might not go away completely and that I might have to keep treating it forever. I would mind to much but my family keeps telling me to flush him and get a new fish. Is there something I'm doing wrong or is he just going to be permanently sick?