I recently purchased this betta from the pet store because I felt terrible for him and thought I could help him get better. He can't swim well at all. He's lower half hangs like he's dragging it and he mostly sits at the bottom of the tank. I put him in a goldfish bowel and lowered the water so that it's just high enough to cover the heater because he has a terrible time swimming to the surface to get air.
I do a 100% water change every day and add prime and stress coat to the water. He's been doing a little bit better over the past few days and is more eager to swim to the surface, but I still have no clue what's wrong with him or how to help. I feed him two pellets of omega one a day and he'll come to the surface for them and practically eat it out of my hand if I let him. I've also given him frozen blood worms as a treat and he happily ate them. He gets excited when he sees me come into the room and tries to swim around a little.
He seems so weak so I'd like to treat him conservatively at first. I'm not sure if he could handle any sort of strong medication. I'd appreciate any help or advice. I really hope I can help get him better.