ill cory

Hi, 2 days ago I got some peppered corydoras - one of them died before I even got to drop acclimate them. The other two are doing well in the tank. I called pets at home and they said I could come get a new cory. I’ve just brought him home today and noticed his fins are a bit ‘teared’ ? Not sure...

I have 7 Cories in a 5 gal tank, I know it isn't big enough but I'm moving them to a 10 gal this week.  I'm just waiting for it to cycle.  Anyway it's only the 7 cories and I've had the for a few weeks.. The water was cycled for 6 weeks before I put them in and they all hid for a day, then began...