Vivariums

So I love the idea of vivariums, but haven't had a reason to think about building one since I put my snakes in tubs- until I decided to get a crestie in a few months. Since then, I've watched several VERY cool and useful tutorials which I'll be putting into play; I'll put links at the bottom for those interested. But, while covering live plants and such, nothing has been mentioned about adding bugs or anything that I've see people on here mention, or about making it self sustaining. What are the steps that takes something from a vivarium to a self-sustaining mini ecosystem?

Oh, and I know cresties can swim (not sure if it's a frequency or not); is it worth putting in a waterfall, or do you think that would make my humidity too high? Do you think it'd be possible to put another species in there- like something as basic as guppies? Just spitballing here, I'm new to the viv concept and I want to know the potential. Thanks for your time!

http://www.youtube.com/watch?v=Lfa7KgsUJ7I - Custom waterful vivarium by LLLReptile
http://www.youtube.com/watch?v=27pkh0m-oCY - Building a crested gecko vivarium by LLLReptile

http://www.blackjungleterrariumsuppl...101_ep_50.html
http://ball-pythons.net/forums/showt...a-Janitor-Bugs


^^ Useful linkage!

The bugs that are important to have are isopods, springtails, and good bacteria. This is achieved by ordering cultures of the various buggies, or going out and hand-collecting. Icollected my isopods, and it was much cheaper. :P Spring tails are a little harder to catch though, simply because they're sooo tiny. Good bacteria can be achieved by using an organic, unsanitized potting soil in your substrate, and making sure you have a good drainage layer, or a false bottom.

a resource for buggie cultures: http://www.thefloridafrogger.com/critters.html

Thank you! Does it matter if you get a starter culture or a well started culture?