NEED HELP WITH CLOWN KNIFE FISH TOP FIN

[JOSCAR05]

So my clown knife fish has had this rip on his top fin. Not really sure what its called. Can anyone please help me? Hes had this rip for a while now and it is not healing. The water is good and hes eating everyday dont know whats wrong with his fin. Heres a picture

 

[JOSCAR05]

any1

 

[Joee3196]

if his fin has ripped than it has ripped just make sure it heals without infection.