4 inch florida just bought yesterday, seemed completely healthy, ate right away, and was doing great earlier this afternoon. Came home later and he's floating at the surface sticking partially out of the water (more than usual for gars) and gasping. He also seems to have a bubble of air stuck under his chin, which I tried to massage out, but it comes right back. Unresponsive to touch, and every now and then tries to dive to no avail. Params are 0, 0, 15. All other fish in the tank are fine. Swim bladder too full? How can I help? I really have no other ideas, please help!