I have a betta fish named Jeremy. He accidentally snagged his back fin on a broken glass stone. I didn't realized the stone was broken before and I removed it from the tank. His back fin was ripped so I got some Melafix at the pet store. I gave it to him for about a week and his fin is doing much better. But then I read online that Melafix is dangerous for bettas. I stopped giving it to him and I am not sure what to do now. Is melafix harmfull? He seamed to doing well. I don't know what to do.