Smaller would b fine. they were very tiny when I got them an I housed them in a 12x12x18 simple exo terra set up till I knew they were eating well an doing well. You know the good old stand by stuff I only have a pair now myself but may get 1-2 more some time in the future. Grow them up a lil an start on a much bigger tank. Then maybe do a more crazy set up for them but defiantly center it all around water. *I keep them at a high humidity witch you don't have to but it helps with them not spending all there time in the water an wandering more around the tank. But they are big eaters. Least these 2 little ones are. I hope to get allot more creative an crazy with my dart frog tank I'm starting. Got the itch to try my hand at some darts. Eekkk lol sort of excited. Lol