What Kind of Salt Should I Use in My Water Softener?

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It would be easy for everyone if there was a single type of water softener salt. But there’s a range of softener salts, in different sizes, consistencies, and purities.

Which type of salt is best for a water softener? How can you invest wisely in the best water softener salt for your needs? We’ll be discussing everything you need to know in this guide.


If you’re looking for the quick answer, the best water softener salt is the purest form of salt: evaporated salt. This salt contains the fewest impurities and is the best value for money.

📰 The Different Types of Water Softener Salt

The most common types of water softener salt are evaporated salt, rock salt, solar salt, and block salt.

Evaporated Salt

Evaporated salt is the highest-quality and highest-purity salt, and is up to 100% pure. Because you get up to 100% salt in each bag of evaporated salt pellets, the cost of this product is usually higher than the cost of all other water softener salts.

Evaporated salt pellets contain virtually no impurities, so they’re clean and produce minimal buildup in your brine tank.

Rock Salt

Rock salt looks like small pebbles or rocks. This salt is more economical than other water softener salts, but there’s a reason for that – it usually has a high calcium sulfate content.

Rock salt

Solar Salt

Solar salt is available in pellet or crystal form, and is formed by evaporating seawater. This type of salt is effective for softening moderately hard water. However, if your water has high levels of hardness, solar salt isn’t recommended.

Block Salt

Block salt is a low-cost softening salt that can be used in a brine tank with a raised water level. It’s important to completely submerge the salt blocks to prevent bridging at the top of the tank. Most manufacturers advise against using block salt in their water softeners, but it is an option.

🆚 Salt Crystals Vs Pellets

There are two main forms of water softener salt: crystals and pellets.

Salt Crystals

Salt crystals are made using the solar evaporation process, which exposes a brine solution (combining salt and water) to the wind. This eliminates the water, and the salt crystals left behind are used in softener salt products.

Salt crystals are small, white, and hard. If your water usage is lower than average, salt crystals will do just fine. But if you get through a lot of water in your home, you should avoid salt crystals, and the risk of bridging – a hard crust forming in the top of the brine tank – is higher.

Salt crystals vs salt pellets

Salt Pellets

Water softener salt pellets, or evaporated salt pellets, are made by evaporating salt water to form crystals. After drying and screening the crystals, they’re then processed into pellets.

It’s common for evaporated salt pellets to be treated with a tasteless, odorless cleaning agent called citric acid, which protects your water softening system from a buildup of minerals.

Pellets are best-suited to homes with an above-moderate volume of water usage or an all-in-one water softening system.

Is it better to use crystals or pellets in a water softener? It depends on your water usage. Pellets are the safer all-round option, but you can use salt crystals if your weekly water usage is low.

🔎 Water Softener Salt Purity

Different types of water softener salts have different purity percentages. But what exactly is water softener salt purity and why is it important?

The purity of sodium chloride for water softeners is a measure of how much salt the product contains. The higher the purity, the higher the percentage of salt. So, a salt product with 100% purity is 100% salt, while a salt product with 84% purity is only 84% salt.

Wondering what else a water softener salt product might contain?

If the salt isn’t completely pure, it may contain impurities like dirt and sediment (from the natural environment), and chemicals and metals (from processing).

It’s not necessarily bad to buy a salt product with less than 100% purity. But those impurities have to go somewhere.

If you buy impure water softener salts, the impurities will build up inside the brine tank. They won’t dissolve into your water, so they won’t affect your water quality. But you’ll need to clean the brine tank more frequently to prevent the impurities from blocking the salt screen and pipe leading to the resin tank.

In short, impure water softener salts are more likely to cause clogging issues than pure water softener salts. You’ll need to keep on top of your cleaning if you plan to use these salts.

Salt mushing in brine tank

🆚 Water Softener Salt Vs Potassium Chloride

There are tens of different types of water softener salt available – but did you know you don’t have to use water softener salt at all?

Some people don’t like the idea of drinking salt in their softened water, even for the anti-scale benefits it offers. Others can’t drink salt, as they may be on a health plan that requires them to follow a low-sodium diet.

The best alternative to sodium chloride is potassium chloride pellets.

Potassium chloride pellets work exactly the same as sodium chloride during the softening process. Water flows into the brine tank and the potassium chloride dissolves into the water, forming brine. This is then used to replenish the resin.

When water flows into the resin tank, potassium chloride is released to replace the calcium and magnesium ions in the water. Water is softened just as it is with sodium chloride.

Potassium chloride pellets aren’t quite as effective as sodium chloride for softening, so you’ll need to set your water hardness slightly higher on your softener to ensure all minerals are removed. Follow the guidance in your user manual if you’re unsure.

🧂 Can You Use Table Salt in a Water Softener?

You probably have a lot of table salt to hand, and it’s understandable if you’re wondering whether it can be used in your water softener.

Table salt is cheap and easy to come across, and in an ideal world, it’d be suitable for using in a water softener.

Unfortunately, table salt is only suitable for using on your food. Table salt granules are tiny, and are more susceptible to mushing – something that happens when salt collects at the bottom of the brine tank, blocking the pipe that leads to the resin tank.

It’s best to stick to professional sodium chloride products that are designed specifically for use in a water softening system.

Water softening and table salt

💯 Best Brands of Water Softener Salt

There are tens of brands offering water softener salt nowadays, and you don’t get the same value from all of them.

When looking for water softener salt, choose brands that offer the highest-purity salt at the lowest cost. This will give you the best value for the money you spend.

Some of our current favorite brands of water softener salt are Morton, Diamond Crystal, and Nature’s Own. You can check out our best water softener salt guide if you want to know more about these brands and their best products.

Should you buy softener salt from a new or emerging brand? Yes, but keep in mind that you’ll be taking a gamble. We prefer to buy from brands with a long history of reliability, and plenty of customer reviews for us to read in our research.

Morton Clean & Protect review
Clean & Protect
Diamond Crystal Solar Naturals review
Diamond Crystal
Solar Naturals
Nature's Own Potassium Solution review
Nature's Own
Potassium Solution
Weight50 lbs.50 lbs.40 lbs.

🏷️ How to Get the Best Deal on Water Softener Salt

Water softener salt isn’t particularly expensive, but there are still ways to save tens of dollars on your annual salt use:

Buy Online

It’s easy to drive to your local hardware store to pick up some replacement softener salt when you need it. Buy buying in-store is usually more expensive than buying online. Your product selection will be limited, and you’ll pay for the convenience of being able to take the salt home with you there and then. If you have the time, order your salt online – you can always request next-day delivery if you’re in a hurry.

Buy in Bulk

In most cases, the more salt you buy at once, the less you spend per ounce. Aim to buy 40-pound bags rather than smaller bags, and buy multiple bags at once if the manufacturer offers a significant discount on bulk purchases. Buying in bulk can usually help you to save on shipping costs, too.

Buy a Quality Product

Buying a quality softening salt product inadvertently helps you to save money. Let’s assume that you pay for a poor-quality salt product. You might be unimpressed with the salt’s purity percentage, and you might even throw out your salt before you finish using it. It’s much better to buy a quality product first time around. The saying “buy cheap, buy twice” applies here.

🧠 Water Softener Salt FAQs

Why is salt needed in a water softener?

If you have a salt-based water softener, it couldn’t operate without salt. This is because salt is an integral part of the ion exchange process.

During ion exchange, calcium and magnesium ions are drawn into the resin bed, and equal amounts of sodium chloride (salt) ions are released from the bed into the water. This effectively exchanges ions, removing all hardness from the water.

Without salt, there would be nothing to replace the hardness minerals, so the ion exchange process wouldn’t be possible.

Ion exchange process

Does it matter what salt I use in a water softener?

Not necessarily. You can use any type of salt, and the brine tank will do its job and dissolve the salt into your water, which will be used for softening. However, using pure salt is better than using salt with a higher impurity percentage. Pure salt deposits less dirt on the inside of the brine tank, keeping your water softener cleaner for longer and reducing the maintenance needed.

What’s the cheapest kind of water softener salt?

The cheapest kind of water softener salt is rock salt. If you’re looking for a budget-friendly option, this type of salt is suitable. Keep in mind, though, that rock salt contains more impurities than other types of sodium chloride. This means that, although you’re saving money per bag of salt, you get less salt per gram than a purer option, like evaporated salt.

What’s the best water softener salt for low-sodium diets?

If you’re on a low-sodium diet, you’ll want to avoid salt in your water softener altogether. Opt for potassium chloride instead, which is a completely salt-free option that can be used in the same way as salt, and is equally effective.

What’s the purest type of water softener salt?

The purest type of water softener salt is evaporated salt, which has a purity of 99% or more. When you shop around for salt, the purity information should be available in the product description. If it isn’t, you’re probably best looking elsewhere.

Do all water softeners use the same salt?

Yes – you can use any type of salt in most water softeners, unless the salt product or the softener’s user manual states otherwise.

Can you mix different types of salts in the brine tank?

Yes, in most cases, you can mix different types of salts in the brine tank. So, if you’ve been using one brand of salt, and you want to switch to a better or more affordable brand, you can do so.

Just be wary if you have an all-in-one softener with a single tank. This type of system needs salt pellets, so you shouldn’t add different types of salt as you may clog up the tank. The same goes for water softeners with no salt screen – use pellets, not crystals, to prevent clogging.

Salt pellets in brine tank

Can you mix salt and potassium chloride in a water softener?

Planning to switch from salt to potassium chloride, or the other way round? The good news is that you don’t have to empty out the entire brine tank when you plan to introduce salt or potassium chloride. Just try to buy similarly-sized pellets or crystals to avoid bridging in the brine tank.

Can we use normal salt for water softener?

No. Normal salt isn’t designed to be used in a water softener, so stick to special salt designed for water softeners only.

Which salt is best for removing iron in a water softener?

Some water softeners are advertised for removing low levels of iron as well as hardness minerals in water. You might be wondering whether these water softeners need a special type of salt to remove iron. The answer is no – it’s the design of the softener itself, not the salt that’s used, that enables it to remove iron.

Does water softener salt contain chemicals?

It depends on the type of salt you buy. Some water softener salt contains chemical additives that prevent the salt from clumping and hardening when it’s in storage. Aside from chemicals, you might also find impurities like rust, metals, and dust in some types of softener salt, which get into the salt during manufacturing. These won’t leach into your water; they’ll just get trapped in the brine tank.

  • Brian Campbell
    Founder, Water Treatment Specialist

    Brian Campbell is a water treatment specialist and water expert based in Denver, Colorado. He's always been obsessed with water quality, and has spent years testing all kinds of treatment devices from simple pitchers and portable devices to complex whole home systems.

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