my flowerhorn is now 4.5 inches and i want to get him fat. how can i do that he doesnt seem to like pellets that much is there anything else i can try to feed him to get him nice and fat?

why do you want a fat flowerhorn? it won't look good. if your flowerhorn don't eat pellets, try feeding him/her bloodworms or shrimp and meat.

You can try market shrimp, the kind that's peeled already. Cut it up into small bite size pieces.

I don't see why you want your FH fat. As in any other organism, fat is not-so-healthy...