On Wed, 22 Mar 2006 14:43:17 +0000, Peter Parry
wrote:


Polyphosphate dosers - Work much the same as Calgon powder and add
small amounts of a chemical to the water to reduce scale formation.
They do not "soften" the water. Need replenishment of the chemical
periodically (about every 6-12 months). This is straightforward and
usually involves just replacing a small cartridge.

Magnetic - No evidence they work in single pass (domestic)
environments but some that they do in industrial recirculation
systems.

Electronic - No evidence they work at all, none have ever been shown
to work in properly conducted tests. No credible theory why or how
they could work.

A couple of UK Universities (Portsmouth was one, I forget the other)
have shown that electronic conditioners *sometimes* have an effect but
have been unable to come up with a definitive explaination as to why
they work in some applications but not in others.

That's not to say I think people should buy them.

sponix