I have a small school of skirt tetras (four black and two white) in my 36 gallon and I've noticed that one of them has half of its dorsal fin ripped off and its anal fin is torn in places. I know they're quite nippy and usually most of them have small tears that heal quickly but this guy is looking pretty beat up. The damage happened sometime between last night and this morning. (S)he still eats and swims normally, just missing some of the fin. Should I treat the tank with anything as an extra precaution? I'm aware of Pimafix and Melafix and could order some online if they're not available at my LFS. I also have a bottle of ParaGuard and GarlicGuard arriving tomorrow. I do weekly water changes of about 20% and condition with Prime. Water parameters are 0, 0 and between 5 - 10. The temperature is kept between 75 and 78 (fluctuates on warmer days.) Along with the tetras, I have platys, danios, a male dwarf gourami and a gold CAE. I know that the CAE will need to be rehomed in the future and I'm 100% sure that he's not the one causing the damage, the DG isn't either. The tetras are always chasing and attacking each other. I can get pictures tomorrow if anyone needs to see them. But in the meantime, do I wait it out and hope the fins heal by themselves or is there something I should do to help out? Thanks!