Hi, I'm wondering if anyone could diagnose something for me. I'm really starting to have problems with my tank with neon tetras, zebra danios and another type of tetra with a red stripe down the middle (sorry it doesn't help that I don't remember. One of the zebras and one of the unknown fish have both developed a similar ailment. They both are looking kind of fat and their eyes are bulging a bit. One of the neon tetras has not been swimming properly and he is finding small currents hard to withstand. What do I do??? I really need your help and would appreciate greatly if you could either help me diagnose it or even tell me what to do about it. Thanks!