face it,aros have a mind og their own. If you eliminate possible other suspects in the tank, Mine boogies to loud music and snaps at his tail left whip then right whip, dude's got rhythm too! I Change his enrironment, rocks, plants, love love love air bubble curtains or bendable wands to swim through. I also use clip on desk lamps with one amber and one blue bulb and he pouts and begs when they get turned off. Put bright foam bobbers in the tank so he looks up too and doesn't develop dropeye because he's a top dweller. I get feeder neons for entertainment. All of these this keep mine from snapping at himself. (yes, aro;s have little doggie brains, not fishy brains) cricket's are a hot item too.
To fix the fin damage, cut the charcoal out of filters or remove and carbon, charcoal and treat with Melafix (bottle has amounts) the stiff is amazing but the carbon/charcoal will deactivate it. Mine just got a 5 day Melafix/stresscoat treatment and he healed really fast. A little aquarium salt seems to soothe them too.
Lastly, get on ebay and order almond tree leaves (usually from singapore or malaysia) throw those in the water and it naturally heals, calms, is an aphrodesiac and the tanin makes the water take on an amber hue, it still is clear though. It promotes calming and its kind of like wow! my aro is almost being normal! (you can find a pack of 20 leaves for like $5)
Zoo's do things like above called habitat enrichment so the animals don't get bored. Keep him preoccupied or maybe the vet will dock his tail for you! (ha ha joke)
