Ive posted this in a few different threads now, but its relevant so ill post it again
In this setup I have a marbled gecko, a coppertailed skink, an eastern water skink and 5 eastern water dragons, as you can see, 1/3 of the floor of the tank is water, with a few areas for the reptiles to climb out (log, gravel up to surface in the front corner). I have some live plants in the water, as well as around 12 guppies (M+F breeders) 2 paradise fish, 2 platties, 2 bristle nose catfish and 2 other bottom feeders (can't remember the name). I also have 2 large fresh water snails and a frog and I'm about to add a few more water plants (dwarf green rush and Riccia)
I have found the AquaOne Aquis500 filters everything very well, no algae blooms or chemical spikes in the water, the fish are all alive and well, and no one has drowned.
I would recommend a living water area in any terrarium setup, it adds so much to the overall feel and when all my reptiles are asleep or hiding, I can still watch the fish