How to Clear Fin rot w/o too many chemicals and easy to dose/manage

[Navfish]

my bettas showing signs of minor fin rot so I was wondering what I should do. He lives in a 5 gallon w a heater w live plants as well. I do weekly water changes and he is perfectly healthy besides his fins! Any recommendations? I have had him for three and a half months

 

[GaryE]

Most cases of fin rot in show Bettas aren't. The fins are larger than they are healthy and in the normal run of things, they tear. It's a reason why they are kept in jars - to immobilize the fish to keep the fins marketable. Once they start being able to move, then the fins become a liability.
I see no rot.
Forgetting the pictures, try describing the fin rot. What is it that has caught your eye? Remember, we only see photos, and you see the fish.