In article ,
"Martin Sykes" writes:
|
| Doesn't boiling it do the trick? - that's why the lime ends up stuck to the
| inside of the kettle. I think if you boil it more than once it gets even
| softer ( but your kettle will suffer more )

Er, I stopped chemistry at 15, some 42 years ago, but ....

Boiling will remove 'temporary' hardness (i.e. that due to
calcium bicarbonate), which will precipate out as calcium
carbonate. But it will not affect 'permanent' hardness (i.e.
that due to calcium sulphate etc.) Things are more complex
that that, but that is roughly what happens. Reboiling once
you have removed the calcium bicarbonate will do nothing.

In most areas, there is more temporary than permanent hardness,
so boiling water does help a bit.


Regards,
Nick Maclaren.