Potassium vs sodium water softener

Last updated on: July 1, 2024.

Softener Salt: Potassium Chloride vs. Sodium Chloride

Are you in the market for a new salt-based water softener system that aims to eliminate water hardness, scale buildup, and hard minerals?

Considering the high pollution levels in the water, and hard minerals, people are drawn to water softeners. Hard water contains a surplus of calcium and magnesium ions along with trace amounts of iron in many parts of the country. Over time, this hard water causes scale build-up and cuts down the lifespan of household appliances.

Moreover, hardness levels in tap water contribute to dry skin and brittle hair. Therefore, the demand for water softeners has increased bringing several types of water softeners to the market.

The two main types of water softening solutions use either potassium or sodium. Both types of softeners have the same function, only differing in what is left behind in the regenerated water.

Here are a few answers to common questions that arise when a choice needs to be made on whether to choose a potassium or sodium water softener. Read on to find everything you need to to make an informed decision.

Which salt is better for a water softener: sodium chloride or potassium chloride?

Nacl Vs KCl For Water Softener

Different Types of Softening Salt

It’s a common misconception that all water softeners are the same. Therefore, we give very little thought to the kind of salts used in the softening process. Results have shown that both sodium chloride and potassium chloride have proved to be effective when it comes to water softening. The difference lies in the fact that potassium replaces the hard minerals in a potassium water softener during the ion exchange process, and sodium replaces the hard minerals in a sodium water softener. 

Sodium chloride softening salt

  • Most common salt used in water softeners
  • Used in eliminating mineral ions substituting it with sodium ions after which it is fit for circulating all throughout the home
  • Water softener system pulls the hard water to be softened into the resin placed in the softener producing sodium ions replacing mineral ions. After this, it conveys the softened water to a different tank


  • Compared to potassium chloride, sodium chloride is more abundant 
  • It is less expensive, five to six times less expensive compared to potassium chloride 
  • To treat the same volume of water, comparatively lesser sodium chloride is used

Potassium chloride softening salt

  • Same in functionality like sodium chloride the only difference being replacement of mineral ions with that of potassium salts 
  • When potassium chloride crystals are used in a water softener, it filters out calcium and magnesium to substitute it with potassium 


  • It is a great alternative to sodium salt and is 99.9% sodium-free
  • Considered to be environment-friendly 
  • As a salt, it is good for gardening
  • Water treated with potassium chloride can add some amount of potassium to your diet which is said to offer several benefits

Which salt is better for water softener systems?

However, there are also other differences between the two that could help you make your decision based on your needs and lifestyle.

The difference in cost

From a price perspective, sodium chloride water softeners are a great choice as they are inexpensive and readily available. Water softeners that use potassium chloride will need three times the amount of potassium compared to sodium chloride water softeners that only need one bag of sodium chloride.

Impact on health

From a health perspective, for individuals who need to be on a low sodium diet, a potassium water softener is a better choice as it reduces the sodium content in the regenerated water.

Similarly, if you have kidney or other renal issues, choosing a sodium chloride water softener would be wiser, as potassium aggravates these pre-existing conditions.

Impact on the environment

From an environmental perspective, potassium chloride contributes a great deal to plant vigor and soil stability. 

Is it safe to drink water softened with potassium chloride?

It’s perfectly safe to drink water that has been softened with potassium chloride. Individuals who have switched from sodium to potassium water softeners have benefited in many ways.

  • Potassium is an essential element the human body needs but cannot produce on its own. Our intake usually comes from fruits and vegetables.Therefore, by drinking water that has small quantities of potassium in it, we can indirectly increase our potassium intake from yet another source.
  • If you suffer from high blood pressure and other heart diseases and need to be on a low-sodium diet, opting for a potassium chloride water softener is the way to go. These types of water softeners actively reduce sodium intake in our daily lives.
  • Potassium is also considered to be great for the environment. From a production standpoint, potassium leaves a very low carbon footprint compared to sodium. Plants also thrive when treated with water high in potassium.

How to dissolve potassium chloride bridge in water softener?

A salt bridge occurs when a hard crust is formed in the brine tank. It leaves a gap between the salt and the water, thereby preventing the salt from dissolving in the water to make brine solution.

salt bridge

Brine is necessary to coat the resin beads and soften water. These bridges form because of high humidity, changes in temperature around the water softener, or by using too much salt in the softener.

Fortunately, you have a few ways by which you can get rid of the potassium chloride salt bridge:

  • A long broom or any long piece of metal or wooden object can be used to push down to the bottom of the tank, through the bridge
  • The handle around the center of the tank can be moved, which will facilitate the breaking of the bridge
  • Hot water can also be poured over the bridge if the above methods don’t work

Can you switch the water softener to potassium?

Yes, it is possible to switch the water softener from sodium chloride to potassium if you have previously used sodium chloride salts. Only a few minor tweaks are necessary before the switch to potassium is made, such as the duration of recharge of the softener. Considering both are salts, potassium can be used as a one-on-one replacement for sodium chloride.

What is the cost of using potassium chloride in water softening systems?

Potassium Chloride Salt

Although there are many benefits of using a potassium chloride water softener, the downside of this is the cost. One of the main reasons potassium chloride is expensive is because extracting potassium chloride from the earth costs a lot more than mining sodium chloride. This cost is added to the price of the water softener.

In addition, a lot more potassium is needed in terms of quantity when opting to soften water with potassium chloride.

Frequently Asked Questions:

How often do you add potassium to water softener?

Most water softeners are equipped with a valve control panel that calculates when salts need to be replenished. How often you add potassium chloride to your water softener will depend on the following factors:

  • The size of your brine tank
  • How hard the water in your locality is
  • How much iron and manganese are present in your water
  • The number of people at home and water usage – larger consumption implies frequent water regeneration. Thus, more salt will be needed.

Is using potassium chloride in water softener good for plants?

Yes, potassium chloride in water softeners has been considered extremely useful for plant growth and soil quality. We can connect the water softener to outside water to use in our gardens and lawns.

Potassium chloride from the water softener can be a good way to ensure that your plants get the potassium component in the fertilizer. Potassium is an essential nutrient for plant life.

Do potassium chloride water softener pellets last longer than salt?

Unfortunately, the consumption of potassium chloride pellets is a lot higher than sodium chloride salts. Potassium chloride pellets will need to be replenished more often. 

Will potassium in water softener get rid of iron?

Potassium chloride can remove soluble iron and manganese from water when it passes through the softener.


When it comes to choosing the most effective water softening solution for your household, the two most common choices are either potassium chloride or sodium chloride.

While both aim to get rid of water hardness and scale buildup, the choice lies in the key differences between the two. The sodium chloride water softener is an ideal choice from a financial standpoint as the salts are inexpensive, easily available, and last long.

In contrast, the potassium chloride water softener is the way forward if you have health conditions that require you to be on a strict low-sodium diet. They are great for the human body in terms of contributing to our nutritional value and are extremely beneficial for the environment. The only downside to using potassium chloride softeners is the cost and upkeep.

Irrespective of the type of water softener you chose, both sodium chloride and potassium chloride are great options and will deliver excellent results.

About The Author

Our Web Producer

Judith— a passionate water treatment specialist — is a waste water management enthusiast, clean drinking water advocate, and someone with deep personal experience and knowledge about various water equipments. Her work was mentioned in countless notable water associations. Previously she was an editor at Water Alliance.