Try frozen silversides espically the ones that are skinned like the omega's. An frozen shrip from jewel i just got a pound of shirimp from jewel for 5 bucks no skin and no tail ready to eat i hope this helps. The freeze dried shrimp, will get expensive if he eats like mine did.
superworms, krill, crickets, pellets, frozen shrimp, foodsticks. Thats pretty much everything worth feeding to aros. Krill will get expensive when your aro gets bigger, so get it on foodsticks, and frozen shrimp soon.