I've seen a few posts inquiring about bulling up your fish. Serious over feeding can be harmful to the lifespan of many fish. Go for quality over quantity. Currently i have an Arowana, motoro stingray, ornate bichir, flowerhorn, and a pair of wolf fish.
I feed earthworms,crickets,superworms,bloodworms(when smaller), pellet, and krill. I also do feeder fish that I gut load with high end pellets, and gut load the superworms with carrots to help with color. Some species just have a slower growth rate, a higher quality diet might assist.