One of my bettas is sick and I'm having a hard time figuring out what is wrong with him and how to treat him. I've had him for about 3 or 4 weeks now. When I first purchased him he acted and looked fine. I kept him in a 2 gal tank. After aquiring other bettas I had to switch some tanks around and for the time being he is in a 1 gal tank. When I switched him over to the 1 gal he acted a little frantic but eventually settled down. A couple of days after switching him I started to notice him laying on his side and he was constantly staying at the top. I noticed when he would try to swim to the bottom he would just float right back up. Then I noticed that his stomach was swollen. At first I thought it may be swim bladder and thought he might have injured it when I switched him over to the new tank but now I'm not exactly sure since that happens so infrequently. Then I thought it may be constipation but he still has a healthy appetite. I've been feeding him about 5-6 pellets once a day-every other day. I haven't noticed any other physical signs of illness. Just can't swim to the bottom, always laying on his side, and a swollen stomach. I certainly hope someone can help. Right now he's just laying helplessly at the top blowing bubbles...
Please help!!!
Thanks.

Thanks.