Like others, at first I was very hesitant about this and very skeptical regarding whether it would actually work. We have a superb Corian kitchen counter-top with a white basin. After a couple of weeks following my installation of the ScaleWatcher 3, the white Corian basin was becoming cleaner and brighter than with our previous salt water-softener unit! Shower and bath water became increasingly more clean-feeling and excellent... leaving no noticeable residue in the tub. Additionally, our toilets became very residue-free and easy to clean.
There are a lot of on-line comments for and against magnetic and electro-magnetic devices. Many jobs depend on the salt-based systems, so some people are (understandably) concerned. Some people contend that it is scientifically impossible for such devices to work. Yet, huge numbers of people give positive reviews of these devices. I did some research and found good evidence by some that there is, indeed, scientific merit to how these devices work. Coey and Cass, for example, used top-notch electron-microscopy to look at the molecules close-up. Their testing indicated that results were to be found at a 99.9% success rate for a change from the calcium to the more pipe and utility-friendly aragonite form of calcium. Additionally, they found that the effect lasts for over 200 hours.... plenty of time for it to have passed through your home's system, such as through the water heater. ScaleWatcher makes claims for less time; but they are likely making claims on the "safe side." I did on-line research and the electro-magnetic devices such as ScaleWatcher get way better results (and way better reviews) than do the simple, cheap magnet devices; the electronic modulating devices help the Lorentz force to work in a much stronger and effective way than merely by simple magnets. (I did duck-tape a few strong neodymium magnets upstream from the electronic unit, to act as "preconditioners," but stationary magnets do not - in themselves - work well enough on their own.) Additionally, as an added note... previous to purchasing this unit, we found (by snooping on-line) that the ScaleWatcher outfit/company continues to get an A+ score from the Better Business Bureau.
If your water has a lot of iron in it... there is a chance (from what we've read) that this method of water conditioning will not work for you. If not, the company offers your money back! The ScaleWatcher company makes a lot of these (in larger sizes) for industry. This unit might seem a bit expensive, but it is hermetically sealed, is guaranteed for 10 years, and is made by a company that pioneered and refined this type of technology. It is being used by a lot of industry and homes in states like California, where regular salt-based water-softeners are illegal to operate due to their effects on the environment (i.e., the groundwater).
If you like to mess with heavy, old-fashioned salt bags and like antiquated (polluting) systems, stick with your old water-softener. We are sure glad that we changed!