He is not in a bowl, he's in a box similar to that of my other two boys. If it's water quality, why aren't the other fish affected? And I had a heater, which brought the temp up to 86F. Nobody but Leaf told me if it was a problem, so I removed it as Leaf suggested. He's trying to scratch his ventrals, not his whole body. That leads me to think that he has irritated fins. Of course I'll do the water change, and I can treat him for fin rot. I know Epsom=internal problem solver, Aquarium= external problem solver. I'll use aquarium salt for him, if he does in fact have a problem. I just want to know if my new betta has a problem with his fins; if so, I'll fix it. I'm not worrying them to death because they're not dead... I'm just trying my best to take care of them properly.
So to sum this up: Should I put the aquarium heater back(86 degrees F)? Should I treat my new boy for fin rot, or leave him be unless it gets worse? And is it possible that his scratching is caused by fin irritation, not water quality issues?