Translations:Water - Biosand Filter/84/en

Yes, the best sand is crushed rock which can be obtained from most local quarries. Crushed rock does not contain the organic matter or salt that is often found in sand from the river or the beach. The crushed rock sand is also more varied in size and shape which makes the filter more effective. The sand must be washed and sifted before being put in the filter so that only the grains of a certain size range are used and nothing harmful is introduced in the filter. The gravel must also be of varied shapes and must be washed before being placed in the filter. Please see our appendix for more information on the best type of sand to use for filtration.