I have a cherry barb only tank, and one of my younger cherry barbs is now showing signs of some sort of illness. He mainly rests on the bottom of the tank, but when he Does swim his tail will go down, and his head will go up. He also seems to jerk his head to swim. This presents a couple of questions 1. what is wrong with my cherry barb? 2. how would I treat it? 3. I have a hospital tank already set up, but there is 5 black neon tetras in it being treated for parasites. Would it be ok to put my cherry barb in there? 4. Would being the only cherry barb in the hospital tank possibly make his condition worse? I have had this tank set up for almost a year and a half. I don't have an expensive test, but all water parameters are listed fine. So far this is the only cherry barb to be effected. The tempature is also a little high at 81.