Testing Your Water Hardness

Testing your water hardness is an important step in proper laundry care to prevent premature wear on fabrics as well as foul lingering odors and loss of absorbency. For more information on how water hardness affects your laundry visit our page, “Dealing With Hard Water and Getting Your Laundry Clean.” For more information on what hard water is, see “What is Hard Water?”


Where Can I Obtain a Water Test?
  • Order online from various free sources such as Waterboss or Morton Salt. (Please note that some of these services can take up to 10 weeks to arrive). Please note that several people have experienced incorrect results with both of these tests. They are not highly recommended by this site.
  • Visit your local hardware store.
  • Take a sample to your local pet store.
  • Take a sample to your local pool/hot tub supply store.
  • Purchase a water test strip online or in store from retailers like Amazon or Walmart.


How Do I Test My Water?
  • Testing your water is easy! Be sure to follow the instructions on the packaging of your water test strip. It is best to test the water coming directly out of your washer but if you are unable to access the water or pipes to the washer, use a nearby sink. Make sure to use a clean cup or bowl to catch the water. 
  • You will want to test your hot water and your cold water, as hot water heaters can kick up minerals and produce a higher mineral content in hot water.
  • If you suspect you have hard water you can treat it as though it is hard by adding a water softener to your wash cycle as suggested in the doc on how to Properly wash in hard water conditions until you are able to test and be sure.


So I Tested My Water, Now What?
    • You will need to follow the directions and compare it to your test’s key in order to get an approximate PPM of GPG value. 
    • Once you have these values, you can look in the table below for general guidelines as to what actions to take in order to get your laundry clean.


Sightly Hard
Moderately Hard
 Very Hard
Exceptionally Hard
Above 300
Above 17.5
No action
Most detergents will be
able to compensate for this level of hardness.
1/4C Borax
1/2C Borax
3/4C+ Borax
1 C Borax or 1 Cap Calgon


By Amanda Perez