On Sun, 4 Nov 2007 19:06:20 +0000, Andy Hall
wrote:

the replacement cartridge says it contains phosphate so I assumed that
the phosphate ions were exchanged with the sodium/chloride ones.

Not really.

AIUI, there is some kind of coating effect on the heated surfaces that
prevents scale from forming

Does it really work?

If it had been ion exchange I would have believed in it but the
phosphate coating of elements sounds to me much like magnetising the
water molecule and all those other daft claims! I am happy to be
proven wrong though.