They are doing effectively as one specimen. Should you add more fish, know the flowerhorn’s tendency for territorial aggression and be prepared to rearrange your tank. Freshwater puffers require really hard-shelled foods to help keep their sharp enamel worn down, and most species will not be safe for community tanks. https://www.reddit.com/user/AquariumOnlineStore/comments/18kak1j/3_musthave_things_while_building_an_aquarium/