I just bought this flowerhorn from a pet-store it was kinda banged up but since it was a flowerhorn I wanted it. So I bought it acclimated it and added it to the tank with the lights off. I noticed his poop was clear and stringy, it would just hang there for awhile. So i found out it had hex so I bought some meds and cleared it up. Since then ive tried feeding it beef heart, brine shrimp, blood worms and pellets he didn't touch any of them. So i read that if you up the temperature it'll start eating again, tried that didn't work. Yesterday I went out and bought 2dozen ghost shrimp and sure enough he ate them. That was the first time I saw him eat, then i put pellets in the tank today and he didn't even notice them. I don't know what to do, I do a partial water change every week. He hides all the time and he's showing black bars. I would also like to note he shares the tank with a red devil in a 55gal. Do i get rid of the red devil, it is significantly larger than him the red devil is about 8-9in.