regular rock salt is what i use but i use it at a ratio of 1 tsp per 5 galons of water. also go to the lfs and get ya some amquelle, its excelent for preventing secondary infection. its got malalucha oil in it and works kind of like methialade or mecurecrome(sp?) does for humans..lol. u know that burning red stuff mom used to put on scrapes when you was a kid! the directions for it are on the bottle. it wont hurt the tanks cycling, but if you have an air bubbler it makes those ALOT more bubbly..lol. im having issues with my 55g ciclid tank now and am using salt and melafix to keep it from spreading. thought it was bacterial n treated the tank(aparently not quite long enough) then when that didnt work i treated for fungal thinking "oh i must have been wrong, its fungus!" .... nope! i should have treated the bacterial for a longer time so im giving them a break because the tank has had something in it for almost 2 months, now! good luck with the fins, and OH....feed him some frozen bloodworms too. theyre higher in protein than freezedried n no swim bladder stuff to worry about. this will help him recover faster im purty sure.(yep...redneck here lol) anywho, fins take awhile to regrow so be patient.
Beaux