My friend has a betta at work in a 1/2 gallon bowl that a plant sits in. She doesn't clean it as much as needed, but I check her water periodically and it is fine. This one is strange, because the fish has a small white growth right above the right eye. It started small, and increased in size to about twice the size of the eye ball. I added a piece of a penicillian pill and over the weekend, the white growth poped or so it seemed. It was still there, but it was flat now. Like popping a pimple. We stopped the treatment and the thing started growing again. We haven't tried the penicillian again, but did try other meds with no change. It is now about 3 times the size of the eye ball and when we put it into a net to change the water, it started bleeding from the tip. Is it possible that it is a tumor? He doesn't like to eat much and doesn't swim around much anymore either.