water purification

[sameem]

Why Costic Soda and sodium hexa meta phosphate use at water purified system?

[Brian_UK]

I don't know, why are they? ;)

Anyway, perhaps asking this question on a water purification forum might make more sense.

Using Google on SHMP came up with many answers, such as...
http://www.freedrinkingwater.com/water_quality/water-science/j29-08-how-is-shmp-used-as-a-dispersing-agent-and-deflocculating-agent.htm

(http://www.freedrinkingwater.com/water_quality/water-science/j29-08-how-is-shmp-used-as-a-dispersing-agent-and-deflocculating-agent.htm)http://www.freedrinkingwater.com/water_quality/chemical/controlling-corrosion-problems-methods.htm

[Tesla]

From Brian's link 452 is related to give us kidney stones and problems processing calcium. But used as a water softener.