My mom has a 75 gal F.O. tank and her lion fish stopped eating about 5 days ago and for the last 2 day is swimming in circles on the top of the water. It's about 3 1/2 years old. Her husband said the are no signs of any infections and said the water quality is good and all other fish are healthy (two tangs and clown). The only thing I can think of that I've noticed was the water temp is right aroung 83. Anybody have any Ideas or is it to late for the poor guy. I would appreciate any help you might have mom is pretty sad.