I would get him onto a floating pellet as his main staple, as the bigger he gets the less effective the FD bloodworms will be. Addition foods are endless, crickets, mealworms, earthworms or any other size appropriate bugs, my aro love miller moths. Just be careful that there are no pesticides. Lots of frozen or freeze dried foods too, krill, silversides,shrimp, etc.
Once your aro is bigger it will be more economical to feed fresh and frozen "people" seafood. There is a large variety of market shrimp, prawns, scallops, fillets, etc. that you will be able to feed your aro. Best thing is to keep up a variety of things.