Who Gives A Fish Forums

I'm no expert on Bettas, but based on what you described, I'm thinking it could be fin rot. I came across this site that has some useful info on it, along with treatment options - https://www.thespruce.com/fin-rot-1378481. Hope that helps and your fish gets better.

I don't think the plants caused the issue with his top fin, it seems pretty smooth and natural. The purple one at the bottom might be a concern, but it's unlikely since it would probably affect his bottom fin more. If it was fin rot, I'd expect to see some damage to his other fins too. I think he ...