I have a 90 gallon tank with 2 silver dollars, a zebra loach, 3 rose lined sharks, 4 glo tetras, 3 dwarf blood gouramis, 2 powder blue dwarf gouramis, a Bolivian ram cichlid, 3 boesmani rainbow fish, 2 clown plecos, and a Cory cat. Within the last 2 days my Cory cat has shredded fins! I don't...