Which Water Softener Salt Is Best for Your System?

Lawrence Bonk
Written by Lawrence Bonk
Updated September 23, 2021
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Westend61 via Getty Images

Sodium chloride and potassium chloride are the two main types of water softener salt

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Hard water can be a major annoyance for homeowners. Though not a health hazard, this mineral-filled water will eventually clog up pipes, cause damage to appliances, and result in stained sinks and bathtubs, among other frustrations. Luckily, science has blessed us with the hard water softener. This modern marvel uses positively charged ions to eliminate all of those heavy minerals from your water supply, resulting in pure H20 that is as soft as morning dew. 

Once you hire a professional to install a water softener, you’ll have to regularly maintain the system. This means keeping the brine tank stocked with water softener salt, as this salt is a key player in the chemical reaction that turns hard water into soft water. But what types of water softener salt are available, and which is best for your system? It’s actually pretty simple.

Types of Water Softener Salt

There are several different options when it comes to which salt to place in your softener’s brine tank, but most systems can handle anything you throw at it. There are, however, some benefits and disadvantages to each choice that are worth considering.

Sodium-Based Water Softener Salt

Of course, most products available for purchase are manufactured using sodium, or more specifically, sodium chloride. Sodium chloride is easy to find, inexpensive, and highly efficient. The downside? Well, it’s sodium. Those on salt-restricted diets may not want to add more to their water supply, even if it only totals around 30 milligrams of sodium for each eight-ounce glass of water.

Sodium-based water softener products are available as pellets, crystals, and block salt. Pellets and crystals are virtually interchangeable but talk to your favorite plumber before adding block salt. These large blocks may not dissolve in the brine; they only work in special tanks.

Now, as any cook will tell you, not all salt is equal. There are a few different types of sodium used with water softeners.

Rock Salt

Rock salt is by far your cheapest option, though it does come with some potential downsides. Manufacturers extract this salt from underground salt concentrates, so it often includes other minerals and associated impurities. Some rock salt is contaminated with calcium sulfite, which can get in the way of your water softener’s ability to dissolve the salt and create a useful brine. This can lead to clogs and other maintenance issues down the line.

Solar Salt

Solar salt is a good option for most homeowners. It’s cheap—though not as cheap as rock salt—and over 99% pure. This means that it dissolves easily inside of your water softener’s brine tank. As a matter of fact, many plumbers recommend the use of solar salt as it can reduce clumping in the tank. Solar salt still includes trace amounts of other minerals and contaminants, however, so some manufacturers may recommend against using it.

Evaporated Salt

Evaporated salt is the most expensive sodium chloride available, but it is also the purest and most efficient. Typically available in pellets and cubes, evaporated salt boasts a purity rating of over 99.9%. In other words, it won’t gum up your softener system, even with long-term use.

Potassium-Based Water Softener Salt

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One popular water softener salt option is not salt at all. Potassium chloride has become a go-to choice for water softener systems for several reasons. It tends to work just as well as sodium chloride, integrates with most systems, and doesn't add any salt to your home’s water supply. Instead, it adds the healthy and essential nutrient potassium. This makes it a boon for many health-conscious consumers. 

Though not all health-conscious homeowners may choose potassium pellets for their water softener system. If you have kidney or other renal issues, doctors recommend a reduced potassium intake. Additionally, potassium chloride is much more expensive than traditional water softener salt options. Those on a budget may opt for good ol’ salt.

Salt-Free Water Softeners

A third option is a salt-free water softener, otherwise known as a salt-free water conditioner. These appliances don’t actually soften your home’s water supply. Instead, they descale water to prevent solids from depositing in pipes and water-using fixtures. They require less maintenance than traditional water softener systems, don’t require salt or potassium to operate, and last just as long, around ten years.

The downsides of a saltless system? First of all, they are expensive to install. Count on paying between $500 and $3,000 for a professional installation, whereas a regular water softener appliance costs between $100 and $1,800. Also, no-salt systems are not that effective with sitting water, such as your well or water heater. These areas can still get significant limescale buildup. 

Remember, sodium chloride, potassium chloride, and even saltless systems will all get the job done. Base your decision on your budget and any environmental or health concerns you may have.

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