Don’t ever feed cooked shrimp more then once a week to a Flowerhorn. If you do make sure it is chopped into thin short strips or very small cubes. Their stomachs can’t handle it very well otherwise. The shrimp daily is way too much protein! Their stomachs and intestines are not strong and easily get infections, bloated, or suffer anal prolapse. I would never feed carnivore food either. I have been keeping Flowerhorns since 2003. I would feed a pellet that is between 34-40% protein. If he doesn’t eat it the first day don’t feed him the next day, then try again the 3rd day. Don’t worry you aren’t hurting him by not feeding for a day or two. In fact, for an adult like you have, many Flowerhorn keepers will not feed their fish at least one day a week to help clear out their stomach and intestinal tract. Foods I feed include: Hikari Bio-Gold PLUS, New Life Spectrum Algeamax, occasional treats are Fluval Bug Bites, Cooked Shrimp(prepared as described above), Cooked and chopped crab with fresh kelp. Vitachem is an amazing product and you can soak pellets in it for a nutritional boost for your Flowerhorn.