Watch out for companies selling "magnetic water softeners" or "electro-magnetic" maintenance free descalers, also known as "physical water conditioners" or "electronic de-scalers". The hallmark of these clandestine operations are that they have no easily traceable address or google map location, only a PO Box mailing address.
Watch out for the "no quibble" money back guarantee - the scam works by the statistics of very few people succeeding to claim a refund however strong the desire. Most of the huckster firms are able to ignore the "no quibble" refund request from clients, instead insisting on checking for any faults on returned units, and hey presto, if they do suspect something however small they can send a new replacement back for the customer to start to re-fit all over again, and so the pantomime gets into full swing, back and forward, until the client gives up after the mounting postal costs to return the units back, phone calls, letters, time, effort, headaches, etc.
No recognised global water quality authority over the last three decades have been able to establish any scientific groundings for the reliable use of any form of low cost domestic physical water conditioners in the guise of small plastic boxes with flashing lights and curly wires, sold for well above 10 or 20 times their manufacturing cost.
On the other hand, traditional ion-exchange water softeners have been around since 1903 with companies such as Permutit and Kennicott pioneering cost effective and 100% reliable whole house water softeners. Ion-exchange water softening is a world-wide success that include blue chip brands such as Clack Corporation along with General Electric and Siemens, all manufacturing high quality, sophisticated, robust water softeners that actually take limescale out of the water rather than leave it in the water.
Modern variations of traditional water softeners now operate on ultra low sodium chloride usage by incorporating metering systems, allowing just a few bags of salt to be used per year for their operation, removing 100% of the chlorides used in the regeneration process, meaning zero sodium chlorides end up in the household water, just trace level sodium well below EU limits.
Strap on pipe magnets and other similar goofy gizmos, are gimmicks sold by the whackiest miracle workers on various websites with secret address locations. They have been sold on internet sites from 20 euros to 200 euros promising to keep households free of lime without the use of salt or maintenance, but they fail to perform, and cannot remove lime from water.
Most of these firms use paid google adverts rather than organically grown highly positioned websites, and their products are not so highly rated on bulletin boards and forums.
All testing carried out by WQA and NSF - the world leading water product testing laboratories show no change in water hardness or total dissolved solids levels regarding the strap on magnet gizmos and therefore since these contraptions first appeared in the 1970's there has never been any certification established to confirm their ability to remove hardness or remove scale to any consistent degree. See WQA.org and NSF.com
This means reduced soap and shampoo use and softer skin are unobtainable by electronic devices along with any effective scale removal from household pipes, that traditional water softeners would guarantee to prevent at a level of 100% for their working life of typically over 30 years for most US made blue chip manufacturers.
Typical electro-magnetic gizmo ;