3-Kolshi Description

Source: MIT

A homemade, three-pitcher filter unit, one of the simplest and most inexpensive ways treat drinking water. The first pitcher contains coarse sand. The second contains wood charcoal and fine sand, and the third collects the filtered water.

Each kalshi has certain media and function:
  • Top kalshi - coarse sand.
  • Middle kalshi - 2 kg fine sand and 1 kg of wood charcoal
  • Bottom kalshi - collection container
A sari cloth is sometimes used as an additional filter between the top 2 kalshi.

Indigenous Appropriate Technology

Benefits & Drawbacks

  • Simple
  • Excellent microbial removal
  • Can be constructed of local materials
  • Income generation
  • Fragile
  • Low flow (1-2 litres / hr.)
  • Irregular flow rate, requires frequent cleaning
  • Availability of cast iron chips


  • Capital Costs: $5.00 US
  • Operating & Maintenance: N/A