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[[Image:siphon1.jpg|thumb|right|150px300px| Principle of a siphon filter]][[Image:siphon2.png|thumb|right|150px300px| Siphon filter as sold in shops]]
The Siphon filter is a candle-type water filter which uses siphon pressure to force water through a high-quality ceramic filter element. The innovative useage of the siphon results in a high flow rate of 4-6 liters per hour. The Siphon filter is very compact, as only a filter element, a plastic hose, and a valve are needed, while existing storage containers can be used. A washable fabric is used as a pre-filter before the water enters the ceramic element. Therefore, protecting the ceramic filter from premature clogging when using turbid water.
The filter is designed as a point-of-use filter in households. The filter element is impregnated with silver in order to increase the efficiency of the filter.
==Suitable conditions ==
{{procontable | pro=
- Easy to use: after 15-20 litres, the upper container has to be refilled
- No safe storage
}}
==History and social context==
==Suitable conditions ==
{{Potential_Treatment_Capacity_table
}}
==Technical specificationConstruction, operations and maintenance==[[Image:siphon3.png|thumb|right|300px| Siphon filter demonstration in Mozambique]]
====Operation====
The filter element is placed in a container with contaminated water, situated about 70 cm above the clean water container. The siphon action is started by squeezing the rubber bulb. The siphon pressure forces the water through the filter element, ensuring a high flow of water.
====Manufacturing====
The Siphon filter was developed and is now produced by Basic Water Needs India, a company based in Pondicerry, India. The ceramic filter is quite fragile, the plastic is robust. Presently, leakage problems are solved by gluing the candle caps under strict quality control. Plastic bulbs are made in one piece from EVA (material used in hospitals for plastic hoses).
[[Image:siphon3It is not possible to produce the filter locally due to lack of quality control and unavailability of raw materials. It might be possible however, to produce some plastic parts. Local production will be applicable if there’s existing industrial infrastructure.png|thumb|right|150px| Siphon filter demonstration in Mozambique]]
====Treatment Efficiency====
====Maintenance====
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.
====Manufacturing====
The Siphon filter was developed and is now produced by Basic Water Needs India, a company based in Pondicerry, India. The ceramic filter is quite fragile, the plastic is robust. Presently, leakage problems are solved by gluing the candle caps under strict quality control. Plastic bulbs are made in one piece from EVA (material used in hospitals for plastic hoses).
It is not possible to produce the filter locally due to lack of quality control and unavailability of raw materials. It might be possible however, to produce some plastic parts. Local production will be applicable if there’s existing industrial infrastructure.
====Estimated Lifespan====
The plastic parts last up to 5 years.
==CostCosts==
{{Treatment_Cost2
|CapCost= € 7 - 9
Figures are assuming filter replacement takes place every year but plastic parts last up to 5 years.
==Country Field experiences==
It is now being implemented in Tanzania, Mozambique, Madagascar, Kenya and India.
==Manuals== ==MoviesReference manuals, videos, and links==
* [http://www.youtube.com/watch?v=j261j90JKZw Youtube movie on the siphon filter]
* [http://www.youtube.com/watch?v=d8bIyjFEbes Youtube movie on the Tulip filter]
* [http://www.youtube.com/watch?v=NSSeHXymkBw CrystalPur advertisement on Cambodian television]
* [[Solution_of_the_week_6|Akvo solution of the week 6]]
==Links==
*[[Solution_of_the_week_6|Akvo solution of the week 6]]
==Acknowledgements==
==References==
* [https://www.diageogivingforgood.com/how_filters_work.aspx information on the CrystalPur filter]
* Safe Water Today: Supporting Global Water Projects [http://www.safewatertoday.org/]