My HM's fins are a bit frayed and kinda resemble a CT. I was told before that he was tail biting. I moved him into a 10 gallon with a heater, some live and silk plants and lots of places to swim around and hide. He's more active now but his fins aren't healing. In fact they look a little worse. Now ther eis a hole in the top fin. I was thinking ammonia burn? I tested the ammonia just in case and its at 0. He gets stress coat and 100% changes 1X a week and smaller changes in between them. can they actually bite holes into their fins??
This is an older pick, the big tear is still there but the ends are a bit more frayed and pointy now.
ETA - this is from a few days ago. If u compare to the pic above you can see how his fins have gotten a little worse.