I have this question posed to me rather frequently: “Is it safe to drink soft water?

My answer is usually something like this…”Well, it depends on what made the water soft, and what else is in the water

By definition, soft water contains less than 1 grain per gallon (17.1 mg/L) of inorganic mineral hardness (Calcium and Magnesium). So rain water falling from the sky is typically soft water, distilled water is soft water, reverse osmosis purified water is soft water, and of course ion exchange softened water is soft water.

Some people are concerned that drinking water devoid of minerals is potentially harmful to their bodies. There are lots of scary stories about pure water leaching minerals out of bones, people dying of hyponatremia and other pseudoscientific nonsense. The reality is (no I’m not a doctor, but I do have a scientific opinion) that unless you’re trying to subsist on water alone, you’re consuming so many other salts, metals and nutrients from your food and other beverages,  that drinking water that is free of toxins would have absolutely no negative effect on your body.

Some people are concerned about hypertension related to consuming “excess” sodium in their diet.

Ion Exchange water softeners attract hardness and release a proportional amount of sodium during the water softening process. For every grain of hardness removed there will be ~30 mg of sodium added per Gallon (7.9 mg/L) in the softening process. The higher the incoming water hardness level, the higher the sodium level after ion exchange softening occurs. There is no salt added to softened water, at all.

For example:

  • If your water is 10 grains hard, ~79 mg/L of sodium will be added to the water.
  • If your water is 20 grains hard ~158 mg/L of sodium will be added to the water.
  • If your water is 30 grains hard ~237 mg/L of sodium will be added to the water.

A typical portion of drinking water is 8 Oz. or 237 Milliliter, so:

  • If your water is 10 grains hard, ~18.7 mg of sodium will be added to each glass.
  • If your water is 20 grains hard ~37.4 mg of sodium will be added to each glass.
  • If your water is 30 grains hard ~56.1 mg of sodium will be added to each glass.

Considering that a cup of milk contains an average of 107 mg of sodium, and a single slice of typical supermarket white bread contains ~170 mg of sodium, this certainly puts it into perspective.

According to the Mayo Health Clinic, in 2010 the Dietary Guidelines for Americans recommended limiting sodium to less than 2, 300 mg of sodium per day, or 1, 500 if you are 51 or older.

Dr. Sheldon G. Sheps, M.D. contributed a very succinct answer to the question at the Mayo Health Clinic’s website (http://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/expert-answers/water-softeners-sodium/faq-20058469).

…The higher the concentration of calcium and magnesium, the more sodium needed to soften the water. Even so, the added sodium shouldn’t be an issue for most healthy adults…In an Environmental Protection Agency survey, the majority of water systems tested had less than 50 mg of sodium per liter. Based on this data, a fourth of a liter (about an 8-ounce glass) of water would contain less than 12.5 mg of sodium, which falls under the Food and Drug Administration’s definition of “very low sodium…In any case, it’s important to keep in mind that the majority of sodium in an average person’s diet comes from table salt and processed foods. Thus, the best way to decrease sodium in your diet is by putting away the saltshaker and cutting back on processed foods.”

He provides an important warning:

“However, if you’re on a very low-sodium diet and you’re concerned about the amount of sodium in softened water, you may want to consider a water-purification system that uses potassium chloride instead. Another option is to soften only the hot water and use unsoftened cold water for drinking and cooking.”

Naturally, the good doctor meant to say “Softening system” instead of “Purification System”, but the gist of the message is accurate… If you are truly concerned about sodium intake through drinking water, use Potassium Chloride salt instead of sodium chloride salt, drink hard water, or process the water further with a reverse osmosis purifier.

I personally don’t enjoy or recommend drinking unfiltered hard water, but as long as water is properly filtered for organic and inorganic contaminants of concern, hard water isn’t going to kill you. Carbon filters and other typical “taste and Odor” filters will not effectively reduce sodium levels in water.

As always, you should look at your situation holistically and consult closely with your local WQA certified water treatment expert to ensure that you’re getting the very best advice and recommendations.