Biosand Filter

1	What is a biosand filter?
2	How does the biosand filter remove contamination?
3	Does the biosand filter remove all bacteria and viruses?
4	What does the biolayer look like?
5	Will the biosand filter take out parasites?
6	Does the biosand filter remove salt from sea water? What about pesticides, industrial contaminants or other chemicals?
7	How is the biosand filter used?
8	How often can water be poured through the biosand filter?
9	How should water from the biosand filter be stored?
10	Why does the filtered water need to be disinfected? Isn't the filter enough?
11	How fast should the water flow from the biosand filter?
12	What if the flow from the biosand filter is very slow?
13	How often should the sand be replaced?
14	Will any material from the biosand filter dissolve into the water and cause a health problem?