Best Water Softener Hardness Setting to Control Water Hardness

What Should My Water Softener Hardness Be Set At?

Do you have a water softener? If so, you’ve probably wondered what the hardness should be set at.

Water softeners are a great way to improve your water quality, but they can be confusing to operate. It’s very important to know how they work and how to change the hardness setting. That way, when it comes time to set up your system or change its settings, you can do so confidently and effectively.

You don’t want to mess around with something as important as your water quality – especially if hard water is already causing problems in your home like scaling on faucets and appliances or soap scum buildup in showers and tubs. But what is the right hardness level for your water softener?

In this blog post, we will discuss the different hardness levels and what they mean for you and your water softener. We will also provide tips on how to find the right hardness setting for your system and how to optimize its performance. Continue reading to learn all about what the hardness setting should be for your water softener.

How Water Softeners Work

Water softeners remove hardness from water through a process called ion exchange. In an ion exchange system, water passes through a tank of resin beads. The resin is able to attract and hold minerals like calcium and magnesium (the hardness minerals).

When the hard water enters the tank, it comes into contact with the resin beads. The minerals that make up the hardness bind to the resin, and the hard water is then able to flow through the system without any of those minerals. The resin beads are periodically cleaned through a process known as regeneration so that they can continue to remove hardness from the water.

Regeneration involves flushing the resin beads with a saltwater solution. This removes the minerals that are bound to the resin and replaces them with sodium. Once the resin has been regenerated, it is placed back into service where it can continue treating your water.

Read my Ultimate Guide to Water softeners for more information.

Why the Hardness Setting Matters for Your Water Softener

The level of hardness in your water will determine how often your system needs to regenerate – and therefore, how much salt you will need to use. Your water softener isn’t able to measure how soft your water is. It relies, instead, on settings like hardness to tell it when to regenerate.

My design guide for water softeners provides a lot more information about this and a lot more.

Water softener hardness setting too low

Salt Level setting
The correct hardness setting is critical to producing soft water and minimizing salt usage.

If the settings you enter aren’t accurate, your water softener won’t operate at optimum levels. Setting the hardness too low would result in poor removal of hardness from the water – your water might not be as soft as you want it to be. This would allow hard water into your pipes where it could cause scaling and into your appliances where they might be damaged.

Water softener hardness set too high

If you set the hardness too high, your softener will regenerate too frequently. This wastes water and uses more salt than you need.

The key here is to set your hardness level properly, so your water softener is removing all of the hardness without wasting water or using a lot of salt.

Determine How Hard Your Water Is

Water Hardness and units of measure
Water hardness is measured in grains per gallon (gpg) or parts per million (ppm).

The most important step in setting your water softener’s hardness level is to determine how hard your water actually is. You can do this by testing your water or calling the water department if you’re on public water.

Testing your water’s hardness

If you want to test the hardness of your water, there are a few ways to do so. One way is to use a home test kit like the Water hardness Test Strip from LaMotte. This test strip measures the calcium and magnesium levels in your water, so you can get an accurate measure of how hard it is.

Another way to test your water’s hardness is to send a sample off to a lab for analysis. This will give you more accurate information about the mineral content of your water, as well as other information like pH and alkalinity.

Lab testing is the most accurate way to measure water hardness, but it can also be the most expensive. If you only need a general idea of how hard your water is, then using a home test kit is a more affordable option.

Calling your water department

If you’re on public water, you can call the city or county to find out what the hardness level is. They routinely test the water and should be able to give you a range of values that tells you how hard your water is.

Measure the iron in your water

Water softeners don’t remove iron very effectively, but they are affected by the amount of iron in the water. If there’s a lot of iron in your water, then the hardness level needs to be set higher.

The best way to determine the iron level is to test your water. There are several home test kits that provide accurate information. These tests are inexpensive and simple to use.

Setting Your System’s Hardness LevelMechanical timer control system

Once you’ve determined how hard your water is, it’s time to set your water softener’s hardness level. This setting tells the system how much calcium and magnesium are in your water which is used to determine the regeneration cycle.

Step 1 – Measure your water hardness and iron levels

The first step in setting the hardness level for your water softener is measuring the hardness and iron concentrations. For homes on well water, the best method is to test your water using either a test kit or a testing laboratory. If you have tap water, call the water department and ask them for the most recent hardness and iron data.

Step 2 – Determine your adjusted water hardness level

Iron affects the performance of your softener. For every 1 part per million (ppm) of iron, add 4 grains per gallon to your hardness level.

Let’s consider an example where the iron concentration is 1 ppm and your hardness level is 10 grains per gallon.

  1. Calculate iron correction: Iron correction = 1 ppm x 4 gpg/ppm = 4 gpg
  2. Calculate adjusted hardness value: Adjusted hardness = hardness + iron correction = 10 gpg + 4 gpp = 14 gpg

Here is a little more information to help you with this adjustment.

  • 1 ppm of iron – increase hardness by 4
  • 2 ppm of iron – increase hardness by 8
  • 4 ppm of iron – increase hardness by 16

Too much iron in your water will overwhelm your water softener. If you have more than 10 ppm of iron, you should install an iron removal system before your water softener. Otherwise, you’ll have problems with your softener.

Step 3 – Set water hardness level for age of your system

As your water softener gets older, the resin loses its ability to remove calcium and magnesium from your water. You need to account for this reduced efficiency by increasing the hardness setting.

I recommend the following:

Age of Water Softener Increase in Hardness
0 – 5 years No adjustment
5 – 10 years Add 1 gpg
Older than 10 years Add 2 gpg

Step 4 – Optimize your settings

The optimum regeneration cycle is once every week at 75% of your softener’s capacity.

Why only use 75% of the capacity? Because you want to have some buffer in case your weekly water usage is higher than normal, or if the hardness goes up.

If your water softener has a capacity of 32,000 grains, 75% is 24,000 grains. Use 24,000 grains with a cycle set to 7 days to calculate the settings. This will give you the maximum benefit from your water softener.

Important Regeneration Cycle Settings

Most water softeners allow you to control several operating parameters. The most common settings that you can adjust are:

  • Hardness setting. The hardness setting tells the water softener how much calcium and magnesium to remove from the water. The higher the setting, the harder the water will be
  • Regeneration cycle time. This is how long the regeneration process will take. A shorter time means more frequent regenerations but uses less salt.
  • Salt dose. This is how much salt will be used during the regeneration process. Read more about salt in my article.
  • Time of day for regenerations. You can set your water softener to regenerate at a specific time of day. Ideally, it should regenerate when you don’t normally use water to prevent untreated, hard water from entering your plumbing system.

Factors to Consider

When deciding what hardness setting is best for your water softener, you need to consider a few factors in addition to how hard your water is.

Iron concentration in your water

Iron competes with the hardness in your water for the IX sites in your water softener. You have to compensate for the amount of iron by adjusting the hardness setting of your softener.

For every 1 ppm of iron, add 4 grains per gallon to your hardness setting.

Age of your water softener

The age of the resin in your water softener affects its performance. Older resin becomes fouled and loses its ability to remove hardness. As a result, you need to adjust the hardness setting for older softeners.

  • New softener (0 – 5 years): no adjustment to hardness
  • Slightly old softener (5 – 10 years): add 1 gpg to hardness
  • Old softener (10+ years old): add 2 gpg to hardness

Unusually high water usage

If you have a large family and use a lot of water compared to your neighbors, you may need to set the hardness higher so the softener can keep up with demand. I recommend adding 2 gpg to the hardness setting to account for the unusually high consumption.

Tips and Strategies

I have a water softener and have spent a lot of time optimizing it and adjusting the hardness setting. I’ve learned a few tricks over the years that help me keep everything running smoothly.

Routine quality checks of your water

I check my water quality all the time. I’m not talking about testing it – although testing is important. I’m talking looking for signs of hardness in your water.

Do you see calcium scale on your fixtures or your shower? How well does your soap make suds? Is your laundry starting to look dull and dingy?

These are all signs that you have hard water and need to adjust your water softener.

Test your hardness number every month

One of the key things that I do is use a water test kit every month to measure the hardness of my water. I then adjust the setting accordingly and make sure my softener is keeping up with demand.

If you don’t want to track the timing of when to test your hardness, just do it every time you add salt to your brine tank. The key is to test your hardness on a regular basis.

Monitor your salt usage

Keep an eye on how much salt you use. If it varies more than 20% from month to month, you need to adjust your settings. This is also an indication that you might have bridging in the tank or salt mush has formed. Check your tank and make adjustments as needed.

Water Softener Settings by Brand

Each water softener has unique characteristics and properties that need to be considered when setting the hardness. This article covers the general requirements, but you also need to optimize the setting for your particular brand.

Culligan water softener hardness setting

The hardness setting for Culligan water softeners can be adjusted using the salt dosage.

  1. Briefly press the “Setup/Enter” button on the control panel. The first display you’ll see is “tod,” which is the “Time of Day” setting.
  2. Scroll through the menu options using the “Setup/Enter” button until you see “SLtP”. This is the salt dosage display and is the amount of salt used in pounds.
  3. Adjust the value using the “Plus” and “Minus” keys.
  4. Save the new value by pressing “Status”.
  5. Scroll through the menu screen using the “Setup/Enter” button until the screen is blank.
  6. Press “Status” to exit the programming mode.

Kenmore water softener hardness setting

Setting the hardness level on a Kenmore water softener is simple. You need to know the hardness (gpg) and total iron concentration (ppm) in your water.

  1. Press “Select” button the right center of the control panel. The display will flash the word “Hardness” below a number.
  2. Multiply the iron concentration (ppm) by 5. Add this number to the hardness. If your iron is 2 ppm and the hardness is 8 gpg, your adjusted hardness is (2 x 5) + 8 = 18 gpg
  3. Using the up and down arrow buttons, adjust the number until the display reads the adjusted hardness value. In our example, this is 18.
  4. Press the “Select” button in the center of the control panel once and you will exit the programming mode.

Morton water softener hardness setting

Morton water softeners are easy to adjust. The hardness (gpg) and total iron concentration (ppm) in your water must be determined before you can know what the hardness setting should be.

To set the hardness setting on the Morton water softener, follow this procedure. First, determine what the harness setting should be.

  1. Multiply the iron concentration (ppm) by 5. Add this number to the hardness. If your iron is 2 ppm and the hardness is 8 gpg, your adjusted hardness is (2 x 5) + 8 = 18 gpg
  2. Press the MODE/SET key until the indicator points to HARDNESS. The number 25 will appear in the display (flashing).
  3. Press the UP and DOWN keys to adjust water hardness value to 18.
  4. Once you’ve entered the water hardness value, press MODE/SET to accept.


Why does the hardness setting on my water softener matter?

The hardness setting on your water softener matters because it determines how much hard water the unit can remove before regeneration. Setting this value based on the level of calcium and magnesium in your water will optimize the performance of your water softener and eliminate waste of water and salt.

What is the best hardness setting for my water softener?

There is no one-size-fits-all answer to this question – each household has unique needs that must be considered when adjusting the hardness. That said, based on your water hardness and family size, there is a specific setting that will work best for you.

What are the units for hardness?

Hardness is reported in units of grains per gallon (gpg). This value is a measure of how much calcium and magnesium are in your water. Another unit of measure for hardness is parts per million (ppm) to dissolved solids. This value includes other ions besides calcium and magnesium, but there is a good correlation.

Does my water’s hardness change over time?

The amount of hardness in your water fluctuates over time. This is why it’s important to test your water and adjust the hardness setting of your water softener accordingly.

How do I know if my softener’s hardness setting is correct?

There are several ways to determine if the hardness setting of your water softener is correct. One way is by periodically testing your water’s hardness. Another method is by monitoring for any changes in quality of your laundry, soap suds, or anything else that might indicate hard water problems.

Final Take on Setting Your Water Softener’s Hardness

Water softeners are the best way to get rid of hard water problems. With a little effort, you can find out how your specific system should be set up and what hardness setting is appropriate for your needs.

We hope this article has given you some insight on how water softeners work, what the hardness setting means for your system, and how to set that level.

The Filter Guy

Scott Birch is a water filtration installer and designer. He has worked in the industry for many years and is very familiar with and knowledgeable about residential water treatment equipment. Scott enjoys helping people get the most out of their water filtration systems and ensuring that their homes are getting the best possible quality of water.

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