It looks like bacterial, fungal and fin-rot. What
Fishy friend2 said about the causes. I recommend an anti-microbial medication as a treatment because there are multiple infections and fixing the cause as the long term solution. I prefer to use eSHa 2000, but any medication that claims to kill fungus and bacteria will do (the only one I advise against is Primafix/Melafix).
Treatment
[This disease] is cured with Higher levels of added salt, easing the temperature within the tank to 80 will also help as it will speed up the life cycle of the disease. […]
I'm not trying to pick on you… but where did you read this about fungal infections? This is the cure reasoning for ich (…read on…) and I have never heard fungus life cycles and temperature mentioned in the same sentence before, as salt should be killing off fungus at all stages of its life cycle by creating an environment where it cannot survive. High temperatures *might* help by speeding up the metabolism of the fish itself, but only within its comfort range (which in this case, it is). I am not saying that your advice is wrong, I am only asking you to explain your reasoning further as it is flawed based on what I know.
Also worth keeping in mind that the fungus and bacteria that are causing this infection will likely benefit from the increase in alkalinity that the salt is likely to cause.
Note to OP: aquarium salt, marine mix will work and rock sea salt (make sure there are no additives), best choice to worst in that order. Do not use just "rock salt" or table salt because rock salt has quite a different composition from salt that is usually found in water and fine salt usually has anti-caking agents in it. Epsom salt will also work, but it is an anti-constipation "cure", so there would be other things to consider if you use that. I still recommend an anti-microbial medication instead of salt as it is more targeted to the problem.
