The Index Project
Index Award 2011 Finalists
Tulip Siphon Water Filter
An innovative, low-cost water filter for families in developing countries

Hundreds of millions of people still use unsafe drinking water sources. Inadequate access to safe water and sanitation services, coupled with poor hygiene practices, kills and sickens thousands of children every day and leads to impoverishment and diminished opportunities for millions more.

The Tulip Water Filter is designed as a point-of-use filter in households. The filter element is impregnated with silver in order to increase the bacterial removal efficiency of the filter and to reduce the recontamination risk of stored filtered water. By using a hose with a siphon approach, the flow per hour multiplies. The innovative design results in a high flow rate of 4-5 liters per hour, while the filter element can be cleaned by backwashing.

A rubber bulb is used to start the flow and to backwash the filter element. To prevent premature clogging of the filter element in dirty water, a washable pre-filter is added. By pressing and releasing the bulb, a valve closes and the vacuum in the bulb starts a siphoning process, passing water through a ceramic filter. Filtered water flows by gravity into a storage container for safe drinking water. When flow becomes too low, by closing the tap and pressing the bulb, most of the collected dirt will be blown out of the filter (backwashing).

Usage of the Tulip Water Filter could improve health by reducing water borne diseases, costs for medical treatment and lost working days.

Designed by
Klaas van der Ven - the Netherlands