Someone else will have to tell you that. I have never used any med on fish other than a parasite med on some silver dollars that I had that came in with anchor worm. The only thing I have ever used is lots of clean water and a little bit of salt.
I use spring water. I'll pick some up on Sunday when I go back and do some water changes for a week or two, see what happens. But some melafix wouldn't hurt to help repair the fins though, right? No chemicals in that, right?