Find Your Water Hardness Number Before You Adjust Anything

Your water softener needs to know how hard your water is so it can regenerate at the right time. If you set it too low, the softener will regenerate too often and waste salt and water. If you set it too high, hard minerals will slip through and you'll see spots on dishes or buildup in pipes. The number you need is measured in parts per million (ppm) or grains per gallon (gpg).

You can find your water hardness three ways. First, check if your city publishes a water quality report—most municipal water systems post this online or will mail it to you. Second, buy an inexpensive test kit from a hardware store (usually $10 to $20) and test a sample from your tap. Third, contact your water utility directly and ask them for the hardness number. If you have a well, testing is more important because well water hardness varies widely and nobody monitors it for you.

Write down the number and note which unit it uses. If it's in gpg, multiply by 17.1 to convert to ppm (the unit most softeners use). For example, 10 gpg equals about 171 ppm.

Key Takeaways

  • Your water hardness number comes from a city water report, a home test kit, or your water utility—not from guessing or using a neighbor's number.
  • Most softeners display hardness in ppm (parts per million), so convert gpg to ppm by multiplying by 17.1 if your test result uses a different unit.
  • Enter your hardness number into the softener's control panel using the buttons or touchscreen, then confirm the setting was saved before closing the panel.
  • After you set the hardness, the softener will calculate how much salt to use per regeneration cycle based on how much water your household uses.
  • Test your water again after one month to confirm the softener is working—you should see no hardness minerals in treated water.

Locate Your Softener's Control Panel and Manual

The control panel is usually mounted on top of the softener tank or on the side. It has buttons, a small screen, or both. Before you touch anything, find your softener's manual—check the manufacturer's website using the model number (printed on a sticker on the tank), or call the company's customer service line. The manual tells you exactly which buttons to press and in what order, because different brands use different menu systems.

If you cannot find the manual, write down the brand name and model number and search online for "[brand] [model] manual PDF." Most manufacturers post them free. Do not guess at the button sequence—pressing the wrong buttons can reset other settings or lock you out of the menu.

Enter Your Hardness Number Into the Settings Menu

Turn off the softener or put it into setup mode (your manual will say which). Most softeners have a button labeled "Menu," "Set," or "Program"—press and hold it for three to five seconds until the screen changes or a light blinks. You should see a menu with options like "Hardness," "Flow Rate," or "Regeneration."

Use the arrow buttons or number pad to navigate to "Hardness" or "Water Hardness." The screen will show the current setting (often 0 or a default number). Delete the old number and type in your hardness reading in ppm. For example, if your water is 150 ppm, enter 150. Press "Enter" or "Confirm"—the manual will show you which button. The screen should display your new number and ask you to confirm. Press yes or confirm again.

Some softeners also ask you to enter your household's daily water use in gallons. If yours does, estimate based on the number of people in your home and how much you shower, wash dishes, and do laundry. A family of four typically uses 80 to 100 gallons per person per day, so around 320 to 400 gallons total. The softener uses this number to decide how often to regenerate.

Save Your Settings and Exit the Menu

After you enter the hardness number, look for a button labeled "Save," "Done," or "Exit." Press it. The screen should return to the normal display (usually showing the current time or a status message). If the screen goes blank or shows an error, press the menu button again and check that your hardness number is still there. If it disappeared, you did not save it—repeat the entry steps and make sure to press save before exiting.

Turn the softener back on if you switched it off. The control panel should show your new hardness setting in the information display. Some softeners show it on the main screen; others require you to enter the menu again to see it. Check your manual to know where to look.

Test Your Water After One Month

Give the softener a full month to work with the new hardness setting. During that time, it will regenerate (clean itself) based on how much water you use and the hardness number you entered. After four weeks, buy another test kit or contact your water utility again and test a sample from your kitchen tap.

The treated water should show 0 ppm hardness or very close to it (under 10 ppm is acceptable). If it still shows hardness, your setting was too low—the softener is not removing minerals fast enough. If your water is soft but you are refilling the salt tank more than once a month, your setting may be too high—the softener is regenerating more often than necessary. Adjust the hardness number up or down by 10 to 20 ppm and test again after another month.

Common Mistakes When Setting Hardness

The biggest mistake is entering the wrong unit. If your test kit gives you a result in gpg but you enter it as ppm without converting, the softener will think your water is much harder than it actually is and will waste salt. Always multiply gpg by 17.1 before entering it.

Another common error is forgetting to save the setting. You press the buttons, see the number on the screen, and assume it is saved—but if you did not press "Save" or "Confirm," the softener reverts to the old setting as soon as you exit the menu. Always wait for a confirmation message or beep before closing the panel.

A third mistake is using a neighbor's hardness number or guessing. Water hardness varies by neighborhood and even by block. Your number must come from your own water test or your utility's report. Using the wrong number means the softener will not work correctly for your home.

Adjusting Hardness if Your Water Changes

If you move to a new house or your utility reports that water hardness has changed, you will need to update the setting. Follow the same steps: test your new water, find the hardness number, enter it into the menu, and save. Some softeners let you change this setting without turning off the unit; others require you to put them in setup mode first. Your manual will specify.

Seasonal changes can also affect hardness. In some regions, water is harder in winter and softer in summer. If you notice your softener is not working as well at certain times of year, test your water during those seasons and adjust the hardness setting accordingly. You may need to update it twice a year.

Frequently Asked Questions

What if I do not know my water hardness and cannot get it tested?

Contact your water utility first—they are required to test water quality and most will give you the hardness number over the phone. If you have a well, you must test it yourself because nobody else monitors it. A basic test kit costs $10 to $20 at any hardware store. Do not guess or use an average number; an incorrect setting will cause the softener to fail.

Can I change the hardness setting myself or do I need a technician?

You can change it yourself using the control panel buttons and your manual. It takes five to ten minutes and requires no tools or special knowledge. If you are uncomfortable with the menu system, a technician can do it for you, but most charge $75 to $150 for a service call just to adjust one setting.

What happens if I set the hardness too high?

The softener will regenerate more often than necessary, using extra salt and water. You will refill the salt tank frequently and your water bills may increase. The water will still be soft, but you will waste money. Lower the setting by 10 to 20 ppm and test again after a month.

Should I adjust hardness if I add a filter or change my water use?

If you add a whole-house filter before the softener, the hardness number stays the same—the filter removes different things than the softener does. If your household size changes significantly (you move in more people or fewer people), you may want to update the daily water use number so the softener regenerates at the right frequency, but the hardness number itself does not change unless your actual water hardness changes.

Why does my softener keep asking me to regenerate manually even though I set the hardness?

This usually means the softener did not save your hardness setting. Go back into the menu and confirm the number is there. If it shows 0 or a default number, re-enter your hardness and press save again. If the problem continues, your control panel may have a battery backup that is dead—check your manual for battery replacement instructions.