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

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.

Potassium Chloride vs. Sodium Chloride: Softening Performance

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

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.