__NOTOC__
[[Image:siphon1.png|thumb|right|150px| Principle of a siphon filter]]
[[Image:siphon2.png|thumb|right|150px| Siphon filter as sold in shops]][[Image:siphon3.png|thumb|right|150px| Siphon filter demonstration in Mozambique]]
==What is a siphon filter?==
==How does it remove contamination?==
[[Image:siphon2.png|thumb|right|150px| Siphon filter as sold in shops]]
==Operation==
After some time, the flow rate may reduce because of clogging of the filter element. In this case, the filter can be cleaned by backwashing. This is done by closing the valve and squeezing the rubber bulb, which forces the water back through the filter element, pushing dirt particles out and unclogging the filter. This backwash option increases the lifetime of the filter element.
[[Image:siphon3.png|thumb|right|150px| Siphon filter demonstration in Mozambique]]
==Treatment efficiency==
The Siphon filter has been tested using a certified method by “Waterlaboratorium Noord”, an independent laboratory based in the Netherlands. It was found that even after passing 7000 liters of heaviliy contaminated water, the filter still removed E. Coli by more than 99.99%. The E. Coli test is used as an indicator for the removal of pathogenic bacteria in water. Water-borne bacteria are responsible for the large majority of diseases caused by contaminated water.