Is this fish difficult to keep? With my first flametail everything was fine until it started to color up. Then it became withdrawn and stopped eating and eventually died. It was not being picked on. I bought another one about 2 months ago from a different shop. The same pattern is appearing. It was swimming all over the tank and eating like a little pig. It is starting to color up, now is losing interest in eating and kinda just hangs around the bottom. All my other fish are doing fine, and the flametail is not being picked on. If I added cichlid salts to the water, would that help? My water is already quite hard. I am at a loss. This fish is so beautiful, I really want to have one in my collection. I am feeding Spectrum Cichlid food every day and blood worms a couple times a week. Thanks!