Guppy Fin Rot?!

I just noticed that one of my guppies has a huge chunk missing from his fin. Is it fin rot? My mollies tend to be pretty nippy too. Could it be them?

 

If it shows up over night, I would guess a nip. Though, what are your water parameters? We don’t want to rule out fin rot altogether!

 

Yeah, it was probably the mollies. My parameters are good and it's not wilted, just a big chunk missing. I can't move any of them right now, but I had plans to in a month or two. Any way I can dispel the aggression better? Maybe more cover and hiding spots?

 

Yes add as many decorations as possible! Also, just in case it is a territorial issue, you could re-arrange all of your decor!

 

Cool

 

The problem only happened when hurricane lane was affecting my area, could the barometric pressure have stressed them?