Excerpt taken from Consumer Reports Magazine, February 2012
Hard water contains calcium, magnesium, and other dissolved minerals. The water is safe to drink, but it can leave a residue on showers and dishes, and deposits inside appliances that use hot water. Over time, that buildup can affect performance and efficiency.
Hard water can quickly clog a point-of-use filter, so you’ll need to use a whole-house water softener. Ion exchange systems, the most common, work by replacing water-hardening minerals with soft sodium ions…Even if your water is very hard, the amount of sodium left behind in softened water should be low. But if you’re concerned, consider choosing a system that uses potassium chloride. They’re usually just as effective at softening water, though potassium chloride costs several times more than sodium chloride to replenish.