I've had Lightning for about a year, he's in a 5 1/2 G tank, heated at a constant 78F, filtered, about 40% WC's every week or two. Lately I noticed his color was faded on his tail, but him seemed perfectly normal, so I chalked it up to age. A few days ago I noticed he is sitting up near the heater, or near the bottom and breathing heavily. Numerous dipstick tests show me Nitrate and Amonnia, etc is all fine. He isn't swimming around unless I tried to feed him and he eats fine (attacked his bloodworms last night like normal), but otherwise something has to be wrong. I figured he has some disease and started some AFI tetracycline. It's only been 48 hours, but when I did the 25% change tonight I added 1TBSP of aquarium salt. Any ideas? :( I've become quite attached to him and am extremely worried.