Potassium Chloride vs. Sodium Chloride Water Softener Salts: Which Should You Use?

Are you team potassium, or do you support sodium?

Woman washing cucumbers in the kitchen sink
Photo: Olena Ivanova / iStock / Getty Images Plus / Getty Images
Woman washing cucumbers in the kitchen sink
Photo: Olena Ivanova / iStock / Getty Images Plus / Getty Images
Highlights

  • You’ll need 25% more potassium chloride than sodium chloride to soften water.

  • Health conditions, like hyperkalemia or hypertension, may require you to avoid certain salts in your water softener.

  • Sodium chloride costs $5 to $10 per 40-pound bag.

  • Potassium chloride costs $50 to $70 per 40-pound bag.

Get quotes from up to 3 pros!
Enter a zip below and get matched to top-rated pros near you.
Geo Icon

Water softener salts play an important role in delivering water to your home that won’t leave behind pesky limescale buildup. But when you head to the store for a salt refill, you’ll notice two major types on the shelves: potassium chloride and sodium chloride. Which one are you supposed to use? Find out the major differences between potassium chloride versus sodium chloride water softener salts to determine which is right for your household.

What Are the Differences Between Potassium Chloride vs. Sodium Chloride for Water Softeners?

Both types of water softener salts work in the same way, but the biggest differences between the two are their costs, performance, and health impacts. Potassium chloride is not quite as efficient as sodium chloride and costs more, but it’s a good option for people trying to limit their sodium intake.

Type of DifferencePotassium ChlorideSodium Chloride
PerformanceNeeds 25% more saltMore effective with less
TasteSalty, metallicSalty
SourcingExtractExtract, evaporation
SustainabilityMore sustainableLess sustainable
HealthHyperkalemia risksHypertension risks
Cost (per 40-lb bag)$50–$70$5–$10

Potassium Chloride vs. Sodium Chloride: Softening Performance

Water softener filled with sodium chloride pellets
Photo: Kevin Brine / Adobe Stock

Although a water softener can use potassium chloride or sodium chloride to soften water, you’ll find that you may need to use about 25% more potassium chloride to soften the same amount of water as sodium chloride.

Regardless of what salt you use, if your water softener isn’t effectively softening water and leaves behind limescale on faucets and hard water stains on your dishes, hire a local water softener pro to inspect your unit and make any necessary repairs or replacements.

Taste Differences

Sodium chloride can leave behind a slightly salty taste in the softened water when compared to hard water. Similarly, water softened with potassium chloride may also have a somewhat saline taste, but it can also have a mild metallic taste. 

Sourcing Differences

Water softener salt crystals or pellets, whether they’re potassium chloride or sodium chloride, are most often sourced through extraction. For sodium chloride, you can also find solar salt, which is a high-quality water softener salt made by using solar power to dry out seawater for the salt it leaves behind. This is one of the purest types of water softener salts, with 99% purity.

Sustainability Differences

Using pitcher to water house plant
Photo: Elena Zaretskaya / Moment / Getty Images

Potassium chloride offers some eco-friendly credentials over sodium chloride. That’s because potassium chloride can be beneficial to plants, making any wastewater more useful and slightly more sustainable. However, because solar sodium chloride salts can be produced using solar power, they may be a better choice for eco-minded homeowners.

Health Risk Differences

If you have any health concerns, you should talk with your doctor about how your softened water could impact those conditions. Potassium chloride water softener salt is popular for people with hypertensive disorders or other conditions that require restricted sodium intake.

But that doesn’t mean potassium chloride is right for everyone. Potassium is essential for humans, but some people can have too much potassium in the blood, a condition known as hyperkalemia. People with kidney disease, diabetes, or other health concerns may need to avoid using potassium chloride for their water softeners. Again, talk to your doctor before deciding on the best product for your water softener. 

Cost Differences

For budget-conscious homeowners, there is a major difference in costs between potassium chloride versus sodium chloride water softener salts. Sodium chloride products cost $5 to $10 per 40-pound bag, while potassium chloride salts cost $50 to $70 per 40-pound bag. Plus, keep in mind that you’ll need to use more potassium chloride.

Frequently Asked Questions

Determining whether you should use potassium chloride versus sodium chloride water softener salts really depends on your budget and personal preferences. If you need to limit sodium intake or have lots of houseplants, it may be worth it to splurge on using potassium chloride in your water softener. Otherwise, sodium chloride costs less and is more efficient.

Yes. You can water plants with water softened with potassium chloride, and this type of salt may actually be a better option if you have lots of houseplants compared to water softened with sodium chloride. Too much sodium can build up in the soil, making it harder for plants to absorb the water they need.

Yes, you can switch to potassium chloride in your water softener. If you already use potassium chloride, you can swap it for sodium chloride. While these two salt products can be used interchangeably for water softeners, be sure to choose higher-quality versions with the fewest impurities to help your water softener run as efficiently as possible.

Need professional help with your project?
Get quotes from top-rated pros.
The homeowners guide to water softener companies
From average costs to expert advice, get all the answers you need to get your job done.
Woman filling saucepan with tap water
Jul 23, 2024
Jul 23, 2024
On average, a reverse osmosis water filter costs around $2,200, but there are a few variables that impact the total price. Learn about them in this guide.
A woman washing her face in the sink of her bathroom
May 21, 2024
May 21, 2024
Water softener repair costs can add up, but they’re almost always worthwhile. Use this guide to see what your project is going to cost before you get started.
Father and son washing tomatoes in the kitchen sink
May 30, 2024
May 30, 2024
If you want clean, less-contaminated water, a whole-house filter might be the answer. Learn how much a whole-house water filtration system costs in this guide.
Chrome tap with open water
Jun 5, 2024
Jun 5, 2024
Water softeners and conditioners are distinct systems that offer different results. Learn about water softeners versus conditioners and when to choose each.
Senior man drinking filtered water at home
Dec 8, 2023
Dec 8, 2023
Filtered water is different from distilled water, mainly in terms of the purification process, health benefits, and cost of the system.
woman turning on faucet in kitchen
Jun 5, 2024
Jun 5, 2024
Water softeners last up to 25 years, but maintenance, usage, and other factors can affect the life span. Learn more about how long water softeners last.
Share project details to get started.