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How To Test for Hard Water

How to Test for Hard Water
You can do a fairly reliable unscientific test to see if you have a problematic level of hard water in your home by doing the following test with liquid dish washing soap:
  • Take a clean empty plastic bottle having a cap (such as a clean, clear pop bottle);
  • Remove the cap;
  • Open your tap water faucet and fill the bottle about halfway with water (8 to 10 ounces);
  • Add 10 drops of dish washing liquid;
  • Shake well;
  • If the soapy solution foams up quickly you are good and the water is not hard;
  • If it does not foam up but instead creates a milk-curd-like or soapy film on the water surface then the water is likely hard.
  • If you have hard water scale build-up on your shower door or white scale on your faucet aerator, this is also another indicator your water is too hard.
You can also send a water sample out for testing to a certified water testing laboratory. Hard water is anything above 1 grain of hardness per gallon. (A grain of hardness is an amount of calcium and magnesium equal in weight to a kernel of wheat).
  • Less than 1.0 = Soft
  • 1.0 - 3.5 = Slightly Hard
  • 3.5 - 7.0 = Moderately Hard
  • 7.0 - 10.5 = Hard
  • Over 10.5 = Very Hard

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