I'm a relatively new pacman frog owner, and I've found one thing out fast- aquariums are a waste of money. I had just bought a juvenile pacman frog one week ago, and put him in a 10 gallon with coir, sphagnum moss, a hiding place, etc. He didn't eat once. I tried earthworms, crickets, superworms. He either ignored them, or retreated into his burrow nervously. Today, I bought a $3 sterlite tupperware container (16 quarts), and transferred him and everything else over to that. He IMMEDIATELY looked less stressed out, and ate three crickets within an hour of the transfer. He's a juvenile now, so when he gets bigger I'll obviously have to get a slightly bigger container.

tl;dr: A pacman frog out in the open is a stressed pacman frog, and a stressed pacman frog is not a hungry pacman frog. Don't spend $20+ on an aquarium, go for the $3 tupperware container. they like it better.