Pure Paani is exploring an array of distinct pump filter prototypes in order to determine which systems work best in low-income communities. Such devices need to be effective and portable while also being durable and affordable. 

The two most feasible filter types include hollow-fiber, ultra filtration membranes commonly used in gravity and RO systems and cylinder block filters used in under-sink systems. Pure Paani is also considering building its own filter media out of stock materials. With these technologies in mind, Pure Paani has developed the following model set.

Model 1.01

• Filter type – under-sink carbon block
• Pump type – syringe
• History – 6 units built and tested

Model 1.02

• Filter type – ultra filter for Kent Gold gravity system
• Pump type – syringe
• History – with 4 filters in parallel, flow rate is 4 liter per minute, bacteria reduction is almost log 4 (10,000 times less bacteria).

Model 2.02

• Filter type – customized media from filter fabric and stock carbon
• Pump type – syringe
• History – theorized model to assess feasibility of filter media manufactured by Pure Paani

Model 3.01

• Filter type – under-sink carbon block
• Pump type – syringe
• History – theorized model to assess feasibility of custom-built housing for standard, 1 carbon blocks for under-sink filters

Model 4.00

• Filter type – ceramic gravity candle
• Pump type – syringe
• History – theorized model to assess feasibility of custom-built enclosure for pump filter, including seating for filter media and syringe chamber.

Model 5.00

• Filter type – hollow fiber ultrafilter
• Pump type – syringe
• History – 2 units built and tested

Model 5.01

• Filter type – hollow fiber ultrafilter
• Pump type – syringe
• History – 1 unit built and tested, model 5.00 with custom check valves substituted with more expensive, prebuilt check valves

Model 5.02

• Filter type – hollow fiber ultrafilter
• Pump type – syringe
• History – 1 unit built and tested, model 5.01 with specialized, quick-connect fitting at inlet and outlet