he came down with hith in a matter of a week. i didn't stop doing water changes or anything. since he started getting hith i started changing the water every 2 days. now tonite he looks 100 times worse and is trying to jump out of the tank and is hurting himself worse. the water parameters are perfect. the only sign of anything is 5ppm of nitrates. at water changes the parameters are normally the same with 10-15ppm nitrates. never any amonia. I don't understand. could part of it be because he is 13 inches long now and can't hardly turn around in the 55 gallon tank? i was going to swap him into my 75 gallon tonite, but I think the stress would kill him alone.