My beautiful 10+ inch FH is not happy! I've had him for over a year and until about two weeks ago, he was just fine. I fed him two different types of pellets and a block of frozen cichlid variety food everyday, with an occasional goldfish or guppy as a treat. Then he just stopped eating - I think it's been almost two weeks now. He turns down all food and mainly hugs the side of his tank, with occasional "freak outs" or spasms. There are no signs of white spots on him or holes in his head. Had the water tested at fish store - only the tiniest trace of ammonia. Have Ammonia Neutralizing Crystals in filter now. Temperature holding at 80 degrees. About a week ago I changed approximately one-third of his water. How long can a fish go without eating? I'm worried sick about him.