I have recently received an [ad for a device](https://web.archive.org/web/20120317053635/http://www.scalewatcher.co.uk/pages/faq.asp) attaching to my inlet water pipe and a power socket, and claiming to massively reduce the scale build-up.

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> This compact, computerised limescale remover uses a coil wrapped around the outside of your main intake pipe to create an electronic force, which changes the physical properties of the scale-forming calcium.
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> Those limescale beasties are literally shocked into shape. Scalewatcher electronically alters the shape of the limescale crystals so they can't stick onto your pipes any more. Instead they just wash straight through your system.
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> Your water doesn't just stop depositing limescale anymore — it actually absorbs and dissolves existing limescale, so, over time, Scalewatcher actually helps to clean up your plumbing!
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I can't think of any mechanism through which it could possibly achieve that, although my knowledge of physics is amateur-level. Could it work?

(It does seem to trigger all the "scam" alarms in me, but now I have a good place where to seek a second opinion!)

P.S. Curiously, it is claimed that the water remains chemically unchanged - which is weird because any device that actually succeeds at reducing the scale buildup will necessarily increase the amount of minerals in the tap water...