http://www.youtube.com/watch?v=EwW-h12wxg8&feature=plcp
[Accessed: 21.11.2012]
Film about the function of a constructed wetland according to Norwegian design (cold climate). The film is made by Maxit the manufacturer of Filtralite an expanded clay product with high porosity and a large surface area. These qualities make the Filtralite very well suited as filter media for treating water.