Solar water disinfection, Kolkata

Drink Pure Germ Free Solar Water


  • Are you aware that one third of the population of the third world countries are deprived of the supply of pure drinking water? As a result of drinking impure water, they are a victim of various water-borne diseases like diarrhoea, dysentery, gastritis, jaundice, cholera and the like.
  • Every year more than 4 crores of people die due to stomach related diseases and among them about 25 lakhs are children the world over. One child dies in every 15 seconds due to water-borne diseases.

A few methods of purifying water:

  1. Boil water for at least 15-20 minutes—this is not hassle free.
  2. Adding chlorine to water—You can add chlorine. However, it is difficult to fix the appropriate dose.
  3. Solar disinfections (SODIS)—Exposing drinking water to sunlight. By doing so, it is possible to get germ free water.

How does solar water work?

a)       The UV rays of sun (320 – 500 nanometers) can render germ free water.

b)       The temperature also helps to make water germ free.

How to prepare Solar Water?


To do

Not to do

  1. Take 500 ml to 2lt. PET water bottles.

e.g.: mineral water bottles, juice bottles, mustard oil empty bottles, etc.

  1. Wash the bottle thoroughly before use
  2. Use only clean and white PET bottles.
  3. Fill the bottles with water up to the tip.
  4. Keep the bottles in the sun in horizontal position from sunrise to sunset.
  5. Keep the bottles on a tin sheet or concrete or asbestos roof or on tiles or anywhere there is enough uninterrupted sunlight.
  6. Collect the bottles in the evening- your `Solar Water’ is ready.
  7. If it is cloudy, keep the bottles for 2 days from sunrise to sunset.
  1. Do not use bottles bigger than 2 lts. In bigger bottles the UV rays do not reach the bottom of water.
  2. Do not use dirty bottles.
  3. Do not use coloured bottles.
  4. Do not keep the bottles half filled.
  5. Do not keep the bottles in a standing position or in the shade, see to it that the bottles get sufficient sunlight for at least 6 hours.
  6. Do not keep the bottles in a damp place or on an inflammable item like paper or straw.
  7. Do not remove the bottles before evening that is, 6-8 hours of sunlight.
  8. Do not remove the bottles before 2 days when it is cloudy.


During monsoons `Solar Water’ cannot be prepared.

Benefits of Drinking `Solar Water’

You can protect yourself and your family and children from water-borne diseases like diarrhoea, dysentery, acidity, jaundice, cholera, gastritis, etc.

You can save on the fuel spent on boiling water for drinking.





Phone: 033 2554-6127. M:09331274409

May 21, 2010 2:45PM