Orange flash Male Aphisto white pimple on tail fin

[joeluis1214]

Tank conditions:
6.8
82f
15g
For a couple a months now I have seen this small pimple slowly grow larger cannot pin point the issue.He is by himself.

 

[MacZ]

Can't see anything concerning in the pictures.

 

[anewbie]

Can't see anything on the fish also that is a bit on the warm side.

 

[Mike Wise]

I agree, photos are just not good enough. Is it the elongate white patch toward the rear and center part of the tail?