Post by James Wilkinson Sword
Why don't water boards in hard water areas filter the water for you? It
would save their own pipes getting scaled up too.
I would thought this is for two reasons: cost and the fact that a small
amount of the salts which cause limescale is actually thought to be
beneficial to the human body.
And it's not filtration, which the removal of solid particles from a liquid
by a fine mesh (metal, paper, ceramic). In the case of hard water, the salts
are dissolved in the water and gradually deposit themselves onto the pipes
in your house. You'd need a chemical reaction in the treatment plant to
convert the salts to something insoluble that would precipitate out - *that*
precipitate could be separated by filtration.