Potassium chloride water softeners have become somewhat of a go-to alternative to classic salt-based water softeners. Even though both softeners rely on ion exchange to soften hard water, there are some key differences to consider.
So, what’s the difference between potassium chloride salt vs sodium water softener salt? While sodium-based salts replace hard minerals with sodium ions, potassium chloride salts replace the minerals with potassium ions instead. Therefore, your water is either rich in sodium or potassium after it’s softened.
In this article, we’ll discuss the advantages and disadvantages of both salts in more detail, as well as benefits to using potassium chloride.

How Potassium Chloride and Sodium Chloride Salt Works
When hard water flows through the softening system, calcium and magnesium minerals in the water are absorbed by resin beads in the system. When these resin beads reach their full absorption capacity, they are washed with a salt solution to remove the mineral buildup. The salt solution and excess minerals are then discharged out of the system to drain.
But how do these resin beads absorb minerals in the first place? Well, on their own they can’t. Their ability to absorb comes from the chemical makeup of the salt solution: Potassium chloride or sodium chloride.
Here is an excellent Scientific American article that explains how it exactly works. To simply put, we can say that potassium (or sodium) ions replace the calcium and magnesium ions that get stuck in the resin. Resin holds the hard minerals, while sodium or potassium is free to flow. Thus, you get mineral free but sodium or potassium rich water.
Also Read: Different Types of Water Softener Salt & How to Choose
Potassium Chloride Benefits in Drinking Water
Potassium chloride is a metal compound composed of potassium and chloride. It is usually in the form of cube crystals and can be purchased at most drug stores and big outlet supply stores. It’s generally available as both powder and tablets.
Potassium chloride water is excellent for insulin deficiency, gastrointestinal infections, diarrhea, vomiting, as well as kidney problems. When the kidneys aren’t able to produce enough potassium on their own, enriching your water and diet with potassium chloride as a supplement is a great way to improve your potassium intake.
In general, potassium can help with everything from muscle contractions and nerve function to heartbeat regulation and cell function.
Potential Side Effects
As we mentioned above, potassium chloride salt will enrich your drinking water with potassium, while salt-based softeners will do the same with sodium.
High sodium intake isn’t considered safe and can lead to health complications. However, it’s worth noting that water softeners don’t increase sodium levels to such dangerous levels, unless you have very hard water and have to use large volume of salts.
The best way to understand if your sodium softener salt poses a danger to your health is to send your water for testing. If you’re on a low sodium diet, sodium levels in the water shouldn’t be over 20 milligrams per liter (mg/L).
If you want to switch to potassium salts to avoid excessive sodium consumption, you should be aware that too much potassium can also have negative side effects, especially for people with pre-existing conditions.
Not only is potassium chloride safe for your plants, it’s also a fertilizer that will be beneficial to their health. Your plants will appear greener and grow in quicker spurts if you plug their water supply into your potassium chloride water softener.
Mixing potassium and sodium softener solutions is a great choice if you want the best of both worlds: cut down on your sodium intake and keep potassium from burning a hole in your pocket. Potassium chloride salt is more expensive than sodium.
It makes absolutely no difference to your water softener if you choose to use potassium chloride or sodium chloride. The process is still the same—magnesium and calcium in hard water will be exposed to the resins in the tank and disposed of.
You will find potassium water softener solutions in most retail stores that deal with salts, mass merchandise retailers, hardware stores, as well as farm and ranch stores. You can also try convenience and grocery stores.
Is It as Effective as Using Sodium Chloride Salt?
There have been studies to back up claims that potassium chloride is just as effective as sodium chloride when it comes to water softening.
So, why isn’t everyone using potassium chloride for their water softeners? Well, as it turns out, salt-based softeners are a lot more affordable. Potassium softeners are usually double the price of salt-based ones. By the looks of things, potassium solution prices will keep climbing with no end in sight.
Also, while potassium salts are effective at removing minerals, consumers often complain about a metallic or bitter taste in the water. This is more likely to happen if you have to use high amounts of salts to purify the water.
In Closing
The bottom line is that whether you use potassium chloride or sodium chloride comes down to your personal preference. If it’s important for you to have less sodium in your water and the additional cost of using potassium chloride is manageable, then the decision is a clear one.
Good morning,
Periodically, the first taste of water in the morning, causes an automatic spitting out reaction. We can’t describe the “taste”. It seems to be less about that the taste than the “texture”. It’s undrinkable, and affects coffee, etc. We’ve discovered that we can run the washer or dishwasher and the water improves, but no one seems to be able to tell us what is happening to our previously spectacular well water. Reading your article gives us some hints. Can you offer any insight? We use potassium chloride as a softener though we miss the hard water we had. (Our plumbing does not)
Thank you.
Elssa Green
Hi Elssa, thanks for reading. It sounds like you have well water. It some parts of the country, water can smell and taste funny if it’s sits around for a while. So, that may explain the first thing in the morning description you gave. The west coast of Florida is often like this. It could be that you would benefit from a whole house water filter to accompany your softener.
An aspect of use KCl no one mentions is the corrosion of metal components. If one uses KCl they will see corrosion of valves, such as showers or the nipples of metal pipes. Is it easier to use NaCl than replace toilet valves or faucets ?
Hi Craig, thank you for your comments. Our experience and those of others that have been in the field for many years says that this may be true from a chemical/physical perspective of HCL acting different than NaCL, but ultimately the impact not being anywhere near the concern that you’re highlighting.