melafix is great, just put the fish in a hospital tank (so you don't have to dose the whole tank), and treat it, make sure there is a lot or aireation in the tank though. and that should do the trick, a little bit of a ripped fin isn't too mich to wory about, i get one fish a week who gets a small 5mm rip in his/her's fin and by the end of the week its as good as new. although is it is a bit rip and its getting bullied then its best to hospitalise untill healed. scrapes should be hospitalised because they are a bit more serious.
