Angelfish fin rot?

[Sean]

Hey all, we have an Angelfish here who I think is experiencing fin rot?: See pics

But no other fish in the community are experiencing any issues. Water balance and ph is all checking out healthy as can be, no issues or obvious causes. I have been cleaning the water and tank but doesn’t seem to be making any change. So looking into the interwebs I am seeing that aquarium salt can be an effective fungal or bacterial killer if used right. Since I have live plants in the main aquarium I didn’t want to disrupt that balance. 
 

I have started him today in a small isolation tank along and planning to change the water daily with 2tsp aquarium salt / gallon for next 7-10 days. Does this sound like a good plan or should I just follow the directions on the article these guys posted from coop and just do antibiotics?

[Kirsten]

I think salt would be a good place to start. See if it helps. If not, you can move up to the maracyn.