Testing the performance of a water filter for removing bacteria - one experiment.

Most water filters at home become black box. You do not know the quality of water going in neither do you know the quality of the water coming out.

1. If you have purchased a water filter to remove bacteria - such as a candle filter or a UV filter here is one way you can check how the filter is performing. This is called the H2S vial test to check for the presence or absence of e.coli an indicator bacteria for more harmful bacteria in the water
2. Buy some H2S vial test bottles .     One manufacturer is                                                              Water Health Laboratories 4, Hydel Road, Industrial Area,
   Roorkee - 247 667 INDIA
   Tel: +91 (1332) 265320, 270053
   Fax: +91 (1332) 274950
   Cell: +91 94120 74490 (Dr. S.K.Sisodia)
3. Pick a water sample of the water going in to your filter and fill it till the blue line visible on the bottle.
4. Observe for 48 hours. If the water turns black as in the bottle to the leftmost then the water has e.coli. If it stays brown as in the water bottle to the centre then there is no e.coli in the water.
5. We tested it with our Tata Swach filter and here is the result visible. The input water had e.coli as indicated in the left most vial. After getting the water through Tata Swach the water did not turn turn black as in the centre vial showing the filter was doing its job of removing harmful bacteria.
6. Try it with your water filter and see the result for yourself.

The H2S vial test for e.coli

The filter we tested for performance. It passed with flying colours