I bought some pimafix to dose my whole tank with him in it what do you guys and gals think ???
It does look like fin rot, so I would quarantine and then treat. Just to be safe.
Doing more frequent water changes and keeping the water pristine will allow the fin to heal naturally over time. If there are no inverts or guppies in your tank, you can also dose some aquarium salt since your case seems to be a little more advanced than just a little fraying of the fins.
I see the combination of multiple diseases here, i can tell for sure it is a clamped fin disease, i see a hole on the fin which is starting to get infected by the bacteria, is your betta alone in its tank?? what kind of decoration you keep in your tank? please provide me with a short description of your aquarium.
I have guppies and they do fine with aquarium salt. Have never had an issue with it