Water in the home may be “hard” or “soft,” depending on its mineral content. Water that contains more than one grain of calcium and magnesium per gallon is said to be “hard.”

In the United States, 85% of the country has hard water. Water is soft when it falls from the sky as rain. As it travels through rock and soil, it picks up particles of calcium, magnesium, iron, lead and other minerals.

Unless you have a private well, your tap water is processed by a municipal water treatment plant to remove some of its mineral content and other impurities. Depending on the type and amount of processing, water softness will vary from place to place. Still, in most of the United States, water is relatively hard when it leaves the treatment plant.

Calcium and magnesium are the two primary hard water culprits. Because of them, water becomes hard, reducing the ability of soaps to suds and clean, leaving a dingy gray residue on clothes, and spots on dishes.

Hard water is more abrasive than soft water. The tiny mineral particles combine with soap curd or detergents to become like little pieces of rock pounding away at clothing fibers and fragile glassware. Over a period of time, the structural integrity of the product is weakened. This means glasses can become etched and the life of clothing can be reduced.

Skin and hair are affected by hard water. A greater amount of shampoo and soap is needed to clean and hard water doesn’t rinse as well as soft water. That means soap residues remain, leaving skin susceptible to blemishes and hair less shiny.

Hard water is also tough on plumbing. It can cause scale to build on water heaters and pipes, limiting the water flow, reducing the life of the product and increasing operating costs and maintenance of water-using appliances.

Water hardness is corrected by the use of a water softener (often referred to as a conditioner). The hard water is passed through a tank containing resin beads coated with sodium ions or, in some cases, potassium chloride ions. The calcium and magnesium ions are exchanged for the sodium ions, thus softening the water. When the beads have trapped all the hardness they can hold, the unit is regenerated with salt brine to replace the hardness ions with sodium ions. The unit is then ready to soften water again.

Studies have found that soft water saves time and money in the home.

• Soft water activates detergent or soap to make a smaller amount (up to 55% less!) work more effectively.
• An Ohio State University study found that softened water cut the time required for house cleaning from almost 4 hours to less than 2 ½ hours.
• Home water heating costs can be reduced by as much as 20% with softened water; costly plumbing repairs can be reduced too.
• Sheets washed in soft water last a lot longer than those washed in hard water. Sheets washed in soft water can take 32% more washings.