Fin Rot is not healing

[jellybum]

My betta developed fin rot about 4 weeks ago and I treated him with Bettafix for the recommended time twice. Although his fin rot has not gotten worse per say, I have still not seen any sign of healing. Throughout this entire process he has shown no behavioral symptoms and is still very inquisitive and happy in his home. Here are pictures of him now. Any advice on what to do next would be appreciated.

 

[Aiken Drum]

Do you know your water parameters?

What is your water change routine?

Keeping water pristine will be of huge benefit to the healing of your fish.

 

[jellybum]

I do a 100% water change once a week since he is in a smaller bowl. The temperature of his water is about 73 F.