Q Are no-salt water softeners effective? Is there real science behind their operation?
A A water softener is a water treatment system that uses salt to remove minerals responsible for creating hard water, such as calcium and magnesium, and replaces them with soft minerals, such as sodium and potassium.
The no-salt system you're referring to is not a water softener and does not remove those minerals. Instead, salt-free units often called "water conditioners" or "descalers" can help reduce the buildup of lime scale (that hard, chalky white substance that you see in dried water spots) and other chemicals.
Water conditioners, which typically fit around a pipe, are said to change the chemical structure of minerals in water as it travels through the pipe, by using magnets, electrical current and crystallization polymers. The descalers prevent those solids from being deposited inside pipes and on fixtures.
They're not entirely effective, because places where water sits -- in your water heater, for example -- will still get a buildup of scale. However, no-salt systems don't add chemicals to the water and there also is no waste water, as there is with water softeners.
Some no-salt systems work better than others, of course. Some are effective at preventing scale, but they will not "soften" the water, allow you to use significantly less soap or make your clothes whiter and brighter, as many claim.
Here are some reasons you might want to opt for a water softener instead of a water conditioner:
•Hard water can reduce the lifespan of appliances such as dishwashers, ice makers and washing machines and add additional wear to your clothes.