You'll find those "small" containers to work a whole lot better than a 10 gallon tank.......These animals are ambush hunters, so a small Frog in a large tank with a few crickets isn't going to work.......They have to be trained or really well established for a setup like that........

I keep all my Ceratophrys aquatic - It's convenient and works.......One of the few things I learned early on and still practice.......You just acquired this animal, and put it in a setup that it will more than likely not thrive in, so I would back track........Put the animal back in that small container, put just enough water to cover the bottom, put it in a dark place, then feed untill the animal is established in your care.........