Hard Water or Soft—What’s the Difference?

Soft water is water in which the only ion is sodium. Hard water contains various levels of dissolved minerals, most often calcium and magnesium, and sometimes lime.

The ions get into the water when it seeps down through layers of limestone and chalk permeated with these minerals. If you’re reading this, you’re probably already aware that Albuquerque, and New Mexico generally, are in one of the hardest-water areas of the entire United States, with levels of chemicals at or exceeding 10.5 grams per gallon.

What this means is that using hard water to wash or clean things can be quite difficult. For one thing, it takes much more soap, detergent or cleanser to do the same amount of cleaning. The soap doesn’t dissolve into rich, bubbly lather; the chemicals react with it to form insoluble compounds called stearates. These appear as film on the water and scum on whatever is washed, including you; they mean dingy-looking clothes, spots on your dishes and glassware, cloudiness in your swimming pool and stickiness and dullness in your hair. It will also build up rapidly in your pipes, water tanks and heat exchangers and needs to be removed regularly.

On the other hand, soft water is no prize either. Soap doesn’t work well in water that is too soft; instead of sudsing, it just rinses away before it can do the job. Fortunately, very soft water is relatively rare.

Today, there are many ways to get around the problem of hard water. If you want to clear up all your household water, it can be run through a machine that contains a special mineral salt. You can buy one and have it installed at your house. It is recommended that you soften only the water sent to domestic hot water systems, to prevent or slow damage from scale formation in water heaters. In addition, most dishwashers today have such a built-in “softener”. If it’s only the dingy laundry that concerns you, most laundry detergents today contain softening chemicals; if yours doesn’t, washing soda (calcium carbonate) is easily obtained and added to your laundry along with the usual detergent.