Low-Tech Natural Aquarium by Walsted Method.

Walstad Aquarium
http://www.youtube.com/watch?v=ovXVHoHC6TM&feature=related


Outdoor Aquarium.
http://www.youtube.com/watch?v=X-BXt2B9FVE


Wiki
http://theaquariumwiki.com/Walstad_method

Step by Step Instructions with Pics.
http://thegab.org/Plants/step-by-step-setting-up-a-walstad-type-natural-planted-tank.html