18th October 2006 at 3:33 pm #672
It may be possible for people to make their own filters more cheaply. See the Home made biological sand filter design described on http://www.cms-uk.org/water. Depending on the local material cost it could be a lot cheaper for families to use this design which does the same job in the same way as the concrete ones do. Don’t be put off if you don’t have clay pots available as the cms pages include guidelines for making adaptations.