Find Your Water Hardness Level First
Before you touch any dial or button on your softener, you need to know how hard your water actually is. The softener's hardness setting tells the machine how much mineral content to remove, so setting it wrong wastes salt and water or leaves your water still hard.
You can find your water hardness in three ways. First, check if your city publishes a water quality report — most do, and you can find it on your municipal water department's website by searching "[your city] water quality report" or "[your county] water hardness." Second, buy a test kit from any hardware store or pool supply shop; they cost between $10 and $30 and take about five minutes to run. Third, call your water softener company's service line and ask them to test your water for free — many will, especially if you bought the unit from them.
Write down the number in parts per million (ppm) or grains per gallon (gpg). If you get ppm, divide by 17.1 to convert to gpg, which is what most softener controls use.
Key Takeaways
- Your water hardness number comes from a city water report, a home test kit, or a free test from your softener company.
- Most softener controls use grains per gallon (gpg); if your test result is in ppm, divide by 17.1 to convert.
- Set the hardness dial or digital display to match your water's actual hardness number, not higher or lower.
- After you adjust the setting, run a manual regeneration cycle and test the water in a few days to confirm the softener is working correctly.
- If you have very hard water (above 25 gpg), some softeners need a two-tank setup or more frequent regeneration cycles.
Locate the Hardness Control on Your Softener
The hardness setting lives in different places depending on your softener model. On older mechanical softeners, it is a dial on the control head — usually labeled "hardness," "water hardness," or "ppm/gpg" — that you turn by hand. On newer digital softeners, it is a number you enter using buttons or a touchscreen on the control panel.
Check your softener's manual to find the exact location. If you do not have the manual, search online for "[your softener brand and model] manual" — most manufacturers post them free on their websites. If the manual is not online, call the company's customer service line and ask them to walk you through it or email you the relevant page.
Do not confuse the hardness setting with the regeneration frequency dial or the salt level indicator. The hardness setting is the one that directly controls how much mineral the softener removes from each gallon.
Set the Dial or Display to Your Water's Hardness Number
Once you have your hardness number in gpg and you have found the control, adjust it to match. If your water is 15 gpg hard, set the dial or display to 15. If it is 22 gpg, set it to 22. The softener uses this number to calculate how much resin it needs to regenerate and how often to do it.
On a mechanical dial, turn it slowly until the number lines up with the pointer or indicator line. On a digital display, use the up and down buttons to scroll to your number, then press enter or confirm. Some digital models require you to hold a button for three seconds to enter edit mode before you can change the number.
If your water hardness falls between two numbers on a mechanical dial — for example, 16.5 gpg — set it to the higher number. It is better to slightly over-soften than to under-soften, because under-softening means mineral stays in your water and your softener does not regenerate often enough.
Run a Manual Regeneration After Changing the Setting
After you set the hardness number, force the softener to regenerate when ready instead of waiting for its next scheduled cycle. This tells the machine to recalculate how much resin it needs based on your new hardness setting.
On a mechanical softener, look for a button or lever labeled "regenerate," "manual regenerate," or "regen." Press or pull it once. On a digital softener, enter the menu (usually by holding a button marked "menu" or "set"), scroll to "regenerate" or "manual regen," and press enter. The softener will begin a cycle that takes 30 minutes to two hours depending on the model.
Do not use water while the softener is regenerating. The machine is cleaning its resin and cannot soften water at the same time. If you must use water, turn off the softener first, use what you need, then turn it back on and run the regeneration cycle again.
Test Your Water a Few Days Later
After the regeneration cycle finishes and the softener has been running normally for two or three days, test your water again using the same method you used the first time. If you used a test kit, run it again. If you used your city's report, you already know the incoming hardness, so this test confirms the softener is removing it.
Your softened water should read close to zero gpg or very low — typically under 1 gpg. If it still reads high (above 3 gpg), the hardness setting may be wrong, the softener may need more salt, or the resin may be worn out. Check that the salt tank is at least one-quarter full. If salt is low, fill it and run another manual regeneration, then test again in two days.
If the water is still hard after the salt tank is full, call your softener company or a local water treatment service to have them test the water and inspect the unit. The resin may need replacement, or the setting may need adjustment based on your specific water chemistry.
Adjust Again If Your Water Source Changes
If you move to a new house, drill a new well, or switch from well water to city water, your water hardness will likely change. Test the new water and adjust the hardness setting to match. Many people forget this step and wonder why their softener suddenly stops working well — it is usually because the hardness number no longer matches the actual water coming in.
Seasonal changes can also affect hardness slightly, especially if you use well water. Winter groundwater is sometimes harder than summer groundwater. If you notice your water feels harder in one season, test it and adjust the setting if needed.
Frequently Asked Questions
What happens if I set the hardness too high?
The softener will regenerate more often than necessary, using extra salt and water. Your water will be softer than it needs to be, which wastes resources and shortens the time between salt refills. It will not damage the softener, but it costs more to run.
What happens if I set the hardness too low?
The softener will not regenerate often enough, and mineral will build up in your water. You will notice soap not lathering well, spots on dishes, and stiff laundry. The softener itself will not be harmed, but it will not do its job.
Can I change the hardness setting myself or do I need a technician?
You can change it yourself — it is a straightforward adjustment that takes two minutes. You do not need a technician unless the softener is broken or the resin needs replacement. If you are unsure about your hardness number or cannot find the control, call the company for guidance.
Do I need to change the hardness setting if I add a second softener?
No. Each softener has its own hardness setting, and you set each one to your water's actual hardness. If you have two softeners in series (one after the other), both should be set the same way. If you have them in parallel (splitting the water flow), set them both to your hardness number as well.
How often should I retest my water hardness?
Test once when you first install or adjust the softener, then once a year or whenever you notice a change in how your water feels or looks. If your water source is stable, yearly testing is enough. If you use well water or notice seasonal changes, test twice a year.