Skunk Clown Wounded...Advise?

[SweetReefOH]

I have 3 Skunk Clowns. 2 of which have a festering wound on their left fin. Over the last month, it seems to have worsened. They aren’t attacking each other so I am assuming it’s some kind of LFS infection. I don’t know what I should do to get them healed. Any advise is appreciated.

I do have a 10g QT tank set up with .5 level of Cupramine.

[SweetReefOH]

Anyone? I’d like to help these guys out...

[Wall_Tank]

It’s hard to say from the video.  Are you sure it’s not just an injury....from a fight that you missed?  Bitting fins is pretty common clown attack.  Otherwise, It could be fin rot, which would need an antibiotic, not copper.   Has it been getting worse? 

[SweetReefOH]

It’s hard to say from the video.  Are you sure it’s not just an injury....from a fight that you missed?  Bitting fins is pretty common clown attack.  Otherwise, It could be fin rot, which would need an antibiotic, not copper.   Has it been getting worse?

Ya, they don’t sit still enough to get a good shot of it.
It almost reminds me of a scar. It’s like an “almost healed over” wound. It doesn’t appear to be getting worse, but it’s not looking any better either.
I’ve never experienced fin rot so I was googling it. It’s not widespread like most of the images show. And It’s just the one fin, right where the fin meets the body.
Would it be ok to add melafix to my cupramine tank to try to treat them?

Here’s a little bit better pic of the smaller clown. He appears to have only half his left fin left.