Fin/Tail Rot?
 

I recently bought a 5" lapradei bichir and I've noticed that the end part of its tail and anal fin has turn darker-coloured than the rest of the tail and anal fin and they are torn as well. I'm wondering if it's suffering from fin/tail rot and what should I do to cure it with simple aliments (the LFS near my house doesn't provide special cure for fin/tail rot)?

just maintain gd water parameters. shld recover by itself within a wk.

Should I cut off the dark part or should I let it recover by itself?

dont have to cut it. it will recover by itself.