Published: July 30, 2012

    How to Measure Water Hardness

    What is hard water?
    Hard water is the most common water problem found in the average US home. Hard water describes water containing dissolved “hardness” minerals above 1 GPG. Dissolved calcium and magnesium are most often responsible for hard water.

    How is water hardness measured?
    Most water hardness testers measure or report hard water in grains per gallon, but some laboratories use milligrams per liter, or parts per million.

    One part per million (PPM) is just what it says: out of one million units, one unit is a hard water mineral. Grains or a grain per gallon (GPG) is a weight measurement taken from the Ancient Egyptians, and is the equivalent of one dry grain of wheat, or about 1/7000 of a pound. It takes 17.1 PPM to equal 1 GPG.

    If a test for hard water is measured in parts per million or milligrams per liter you can take the total hardness level and divide it by 17.1 to get hardness in grains per gallon. For example if your water test shows 250 mg/L hardness you actually have 14.62 grains per gallon. You convert milligrams per liter or parts per million by dividing the total by 17.1 to get grains per gallon hardness.

    Most Common Myths About Hard Water

    Hard Water Minerals are contaminants
    Fact: Scientific findings supported by officials from the World Health Organization have shown that drinking water rich with essential minerals, specifically calcium and magnesium, protects good health and leads to lower instances of heart disease and stroke.


    Salt water softeners filter water
    : Salt water softeners do not filter water; instead they exchange sodium for healthy minerals. In other words, salt water softeners take ordinary, chlorinated tap water and turn it into ordinary, chlorinated, salty water. A reverse-osmosis system is then required to remove salt, sediment and chlorine to produce palatable water for drinking and cooking, but only at the kitchen tap. Chlorinated, salty water still runs throughout the rest of the home.

    Hard water is harsh, fades clothes and dries skin and hair
    Fact: Hard water does not fade colors or dry skin and hair; chlorine does. Salt water softeners do not remove chlorine and disinfection byproducts.

    Salt water softeners are safe for the environment.

    Fact: According to Ann Heil, a supervising engineer at the Sanitation Districts of Los Angeles County, automatic salt water softeners waste water and put a salty brine discharge into the wastewater stream. High salts in wastewater streams can harm aquatic life and damage crops irrigated with downstream waters.

    Water with low mineral count is naturally slippery

    Fact: Naturally softened water does not feel slippery to the touch. Salt-based water softeners add sodium or potassium to the water which makes the water feel slippery.

    Salt Based Water Softeners being Banned
    Did You Know Salt Based Water Softeners are being BANNED? – Many communities throughout the US, or even the states themselves, have or are considering legislation prohibiting certain types of water softener brine discharge. Among them, in addition to Texas, are California, Connecticut, Massachusetts,

    Hard Water and Kidney Stones

    Does hard water cause kidney stones?
    Some studies show dehydration increases the chances of having kidney stones, and drinking plenty of water may very well prevent their formation. People living in the southeastern United States may have more kidney stones than people living elsewhere, and it is thought that the cause may be related to temperature and dehydration.

    For example, studies report the highest occurrence of kidney stones in the southern region of the US and the lowest in the West. One study suggested that the higher risk may be due to a higher rate of hypertension in the South and certain dietary habits, particularly lower intake of magnesium and low use of calcium supplements. Higher rates of kidney stones have been reported in areas of Australia where magnesium levels in drinking water are low. Hard water tends to have higher amounts of protective calcium and magnesium, although evidence suggests that the hardness or softness of water does not significantly affect risk.

    How to Test for Hard Water

    If your have problems with soap scum or scale, your may need to test for hard water. Your can purchase water hardness tests online. Type of hard water testers include water hardness titration kits and easy-to-use test strips. Both tests for hard water use color changes to indicate the presence and severity of hard water.

    Interpreting Water Hardness Testing Results

    If your test of hard water results in measurements of less than 1 grain per gallon (17.1 Mg/L or less), your have soft water. Anything higher than this amount indicates hard water:

    Results of Water Hardness Testers
    Grains per Gallon mg/L or ppm Water Hardness
    Less than one Less than 17.1 Soft
    1-3.5 17.1060 Slightly hard
    3.5-7 60-120 Moderately Hard
    7-10 120-180 Hard
    Over 10 Over 180 Very Hard

    Just because test results indicate hard water doesn’t mean you have to live with the damage water hardness causes. Traditionally, salt-based water softeners have been used to treat hard water by replacing hard water mineral ions with sodium ions. While effective, salt-based systems discharge significant amounts of briny wastewater, which has a negative effect on the environment and local water sources. This drawback has lead to several states banning the use of salt-based softeners on environment grounds. In addition, salt-based water softeners increase a home’s utility and water bills. The substitution of sodium ions for hard water minerals can also have an adverse effect on people who require low sodium diets.

    Water softener alternatives with salt free technology offer greener means of controlling water hardness. Water softener alternatives require no electricity, produce no wastewater, and soften water by crystallizing hard water minerals so they no longer adhere to surfaces, thereby preventing scaling. Unlike salt-based water softeners, water softener alternatives with salt free technology do not require homeowners to periodically recharge the system with fresh sodium, greatly reducing maintenance costs.

    Water softener alternatives have another important advantage over their salt-based counterparts. Salt-based water softeners remove calcium and manganese, two minerals the human body needs in trace amounts. These minerals remain in tap water in crystalized form after salt-free water conditioning, so your body continues to get the minerals it needs.