I've had this betta for about six months now. He's always had some slightly curled fins but seems to be in fine health, eats great and is active. A little over a month ago I noticed his fins are looking worse, there's what looks like a lot of tears and rips. I changed out my aquarium plants (they're plastic) for smooth, soft ones without hard edges thinking he was ripping his fins on them because he likes to swim through them. In the last three weeks I've been doing twice a week water changes, maybe about a third of my tank each time, and for the last week I've been using Bettafix in the water. Haven't really noticed much improvement and I'm starting to worry that it's fin rot or some other sort of disease?? I attached a picture of him in his cup from when I was cleaning the tank today.