This video series produced by the Center for Affordable Water and Sanitation Technologies (CAWST) is designed to show, step by step. How to construct and install a concrete biological sand filter. It is free and can be viewed here: https://washresources.cawst.org/fr/collections/714c93ae/how-to-build-a-biosand-filter-video-collection
Français
English
Deutsch
Español
Italiano
Português