I have a guy with some pretty shredded fins and don't know what the issue is. He's in a heated (80 degrees) 5.5 gallon. Parameters are perfect. All plants are silk. I've checked all the decor, he has plenty of hides. The filter is so slow, there's always biofilm. I've kept his light off. I use stress coat and I've recently added IAL. I don't know what else to do. In a FB group it was suggested if it was stress related, he might do better in a smaller tank. I wanted to see what other's experiences were. He's a pretty tail heavy guy. I'm just at a loss. I've never seen him nip, but if he does, his tail always seems worse in the morning.