Let me see, I think I took a picture that would explain how I did the land section better...
ah yes, here it is
As you can kind of see, there were PVC supports that held the land portion above the water line, allowing fish to freely swim underneath it. The tank housed both frogs and fish and all were living happily until the crack. As with any water area, dart frogs are in danger of drowning, but they're much better swimmers than they're given credit for. As long as there are places for them to easily climb out I felt comfortable that they weren't in danger.
I don't know that I've seen my imitators on the ground more than a handful of times since I got them.