Tail biting or rot? pics included

[Friendlyfishies]

Im pretty sure hes biting now, but it started out as rips and possibly mild rot.

Does this look like rot or bites?
More and more vanishes by the day, never caught him biting.
Ive had him for a little over 2 months
This is the progression over the past 2 months

[Friendlyfishies]

When he lost the dorsal fin


Healing



Today




Hes been through treatment with AQ salt and IAL's ...he just moved to a 10 gal to see if the biting will stop if thats what it is, but there was more missing this AM. He still has IAL and his water is kept very clean.

Thoughts...biting/rot?

[sainthogan]

Looks like biting to me. If it is fin biting, that's a very hard habit to break, and it might get worse before it gets better. He will need lots of entertainment to help him stop biting. Lots and lots of decorations (outside the tank works well) and something to play with - like chasing your finger, or putting his food in a water bottle cap so he has to figure out how to get it out, etc.
Good Luck