All my angelfish.....majestic, flame, and lemonpeel angelfish like something called Bioblend bottom feeder fish food by Marineland labs. These are green pellets about the size of a dime that slowly soften. My fish all love them when they are placed on a small rock with a rubberband on the bottom of the tank. They can then peck at them for a couple of hours without them dissoulving and polluting the tank. Don't let the picture of the catfish on the bottle scare you as they are for all types of fish. I know you have a butterfly, but they are grazers like angelfish. They also love Seaweed Selects seaweed sheets placed on a rock with a rubber band. They come in green and red....my fish like both, but the red is softer. Don't bother with lettuce as the nutrition is very poor. Go immediatly to buy some of these items before it is too late for your fish. I find the fish take a lot faster to eating to food on a rock compared to a feeding clip which scares some fish at first. In nature these types of fish graze on rocks all day long. Maybe in time you can get your fish to eat flake or some other items but a lot of older fish caught in the wild may not have been use to the items you were giving and not recognize them as food at first. Good luck, Lesley