Injured black skirt tetra

[Fishmanic]

He's about 4 years old. To me this looks like some fin rot and also the tail sits to one side likes its broken.
Anyone know for certain what the issue is and best way to treat it? @Colin_T @Byron

 

[Bruce Leyland-Jones]

Definitely looks to be in a bad way...with the pop-eyes as well, I'd be thinking bacterial infection. Aquarium salt might be a consideration, but at 4 years old, the fish might be approaching that big warm river in the sky.

 

[Colin_T]

Probably not much you can do for it. Old fish with an infection and problems swimming. Euthanise.