Research on the flow speed throughout the filter pads, has enabled us to keep down the external size of this filter, whilst keeping high mechanical and biological functions. Filtration is achieved at variable speed: the dirty water flows slowly at first, and flows faster as the water is purified.
The organic material penetrates into the inner layers. The colonies of bacteria are therefore able to populate all the useful surfaces for better efficiency and lower frequency of filter cleaning and maintenance. The containers of the second and third stage can be changed separately so that filter media can be replaced in any order desired.