help me!!my arowana anal fins damage...

[apiz]

just bought today..my aro jump(banjar red 15 cm i think) then anal fins got damage..how to do???leave it or give medicine?????help me plss...this is sample picture my banjar red..same like this..i mark this picture where my aro damge...(black colour there)

 

[kritz]

Add antibiotic to your water this will prevent further damage. And keep your water parameters on the level always,

 

[Lupin]

Antibiotics are not necessary. Just do water changes daily until it recovers.