First step is to read this from PUB:
"Sodium silicofluoride is added to the water on its way from the filters to the clear water tank. Fluoridation is a requirement by the Ministry of Health and has been a practice since 1957. It helps in the prevention of dental caries."
Second watch this video:
<iframe width="560" height="349" src="http://www.youtube.com/embed/7aTfyo0Xz_c" frameborder="0" allowfullscreen></iframe>
"Sodium silicofluoride is added to the water on its way from the filters to the clear water tank. Fluoridation is a requirement by the Ministry of Health and has been a practice since 1957. It helps in the prevention of dental caries."
Second watch this video:
<iframe width="560" height="349" src="http://www.youtube.com/embed/7aTfyo0Xz_c" frameborder="0" allowfullscreen></iframe>