Hi Dark just noticed your post today, sorry i didnt reply.
I treated him with the epsom salts for 7 days, his wound seems to of healed alot but there is another problem now.
He seems to be swimming funny, no damage to his fins but what happens is he spends alot of time at the bottom of the tank underneath some wood and when he does surface he swims vertical (head at the top tail at the bottom) or should say when he is sitting still floating on the surface he is vertical.
I have put him back in the main tank he still seems to be eating, i have checked the ammonia levels and they seem to be betweeen either zero or maybe 0.25
Only thing i can think of is that he is reaching that sad age of around 2 years old and its old age.
Maybe its something simple to fix i dont know