I build my waterfeatures using either a sump tank or an internal slow area in the tank it self. eitherway, it's fun. Here is one photo that i scuplted the rock work to look like limestone with a tree root. the waterfall from sump tank is 6' H, and in the enclosure, 4'.
I don't use great stuff as i've seen it fail. I use pond foam and rock it up with vivarium mortar so that i can get a more rock look to it. I also use aqua-via pumps, like rio but better, for anything from a ten gallon to a room sized habitat, they work great! marine depot has great prices too.
For palidariums though, I like to make sure that I have 1" above the water level to eggcrate so that the plant roots don't rot and to ensure that the nitrogen cycle will allow for the gases to contact the plant roots. if your water is touching the roots, many plants will fail with out air. I use 2" x 6" pvc pipe drilled and then the eggcrate, then the screen mesh for enclosures like the exo-terra or such tanks that have water features, and the same but like the wonderfully planned one above, allow for a "pond" area. I still create a streem type water fall on one side or such but the idea is still the same.
I also use water plants to help bring oxygen in and some bacteria to start the cycle. i use tree fern panel on the back that i dip into the water areas to bring that nice soup up to the plant that i grow on the walls.

-----
Thnx,
Deven