What is Water Softener Salt & What Does it Do?

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If you’re considering buying a traditional salt-based water softener system, you probably have some questions about water softener salt.

In this introduction to water softener salt, we’ve shared all you need to know. You’ll find out what salt for water softeners is, what it does, and why it’s needed.

📌 Key Takeaways:

  • Water softener salt is a type of sodium that’s specially designed for use in a water softening system.
  • Salt is used in the ion exchange process, when sodium ions are exchanged for hard minerals in the water softener resin tank.
  • There are several types of salt for water softeners, including evaporated salt, solar salt, rock salt, pellet salt and block salt.

🤔 What Is Water Softener Salt

Water softener salt is a type of salt that’s used in an ion exchange water softener.

This salt is mostly made from sodium chloride. It may also contain traces of potassium chloride, impurities like dirt, and chemicals to enhance the softening process and prevent salt clogs in the tank.

Salt is added to the brine tank in the water softener system. The salt should be topped up to keep the ion exchange process working properly.

Adding salt to water softener brine tank

🚰 Why Do Water Softeners Need Salt?

Water softeners need salt for a process called ion exchange.

Before it can start softening hard water, a softener system draws a brine solution (salty water) from the brine tank into the resin (mineral) tank. Here, the resin beads are loaded with sodium ions from the brine.

Hard water then flows through the resin tank, and the calcium and magnesium ions are attracted to the resin beads.

When these minerals stick to the resin, equal amounts of sodium are released to balance out the charge – resulting in salt-softened water.

Using salt to clean the resin softens the water and eliminates all the effects of hard water, including limescale buildup, decreased efficiency of household appliances, soap scum, skin and hair issues, and reduced water flow.

salt pellets in brine tank

📋 Types Of Water Softening Salt

There are a few types of salt that can be used in water softening systems:

Evaporated Salt

Evaporated salt is considered the best type of salt for softening water because it’s the highest quality and highest purity, containing as close to 100% pure sodium as possible. This salt is typically the most expensive.

Solar Salt

Solar salt is made by evaporating seawater and is usually the most natural salt available. It’s a good choice for moderately hard water and is a more affordable alternative to evaporated salts.

Rock Salt

Rock salt looks like small rocks or pebbles and is the most affordable type of salt for softening water. However, this salt contains the most impurities, so it’s not the most efficient type of salt to use.

Block Salt

Block salt is large blocks or bricks of salt. This salt isn’t ideal for most types of water softeners as it’s difficult to completely submerge the blocks beneath the water level in the brine tank.

Related: How to crush water softener salt

🆚 Salt Crystals Vs Pellets

You can buy salt for water softeners in crystal and pellet form.

Salt pellets are crystals that have been processed into pellet shapes, usually with added citric acid (a cleaning agent that prevents mineral buildup).

Crystals are a natural form of softening salt that are produced by evaporating seawater.

Salt pellets are recommended over crystals in most water softeners, especially all-in-one cabinet-style softeners, because they’re less likely to form salt bridges and clumping at the bottom of the brine tank.

👨‍🔧 You can learn more about salt pellets vs crystals, and read our advice on how to pick the best water softening salt, in this guide.

Deciding between salt pellets and crystals

🆚 Water Softener Salt Vs Potassium Chloride

An alternative to traditional salt in a softener is potassium chloride.

Potassium chloride is a potassium-based salt that has the same role as sodium in the ion exchange process.

The resin beads are loaded with potassium ions, which are exchanged for hardness minerals as water passes through the tank.

The only difference is that potassium chloride isn’t quite as effective at softening tap water, so you’ll need to increase your hardness setting by about 20-25% to accommodate this substance.

Water softened with potassium chloride is free from sodium, so it’s suitable for people on low-sodium diets and anyone who just wants to minimize their salt usage as much as possible.

🏪 Where To Buy Water Softener Salt

You can buy salt for water softeners on various online stores – such as marketplaces like Amazon, third-party sellers, and directly from the manufacturer – as well as in hardware stores, and in big box stores like Lowe’s and Home Depot.

You can usually get the best deal on salt by buying online, but make sure you factor in the cost of shipping.

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❔ What Is Water Softener Salt? FAQ

How does salt soften water?

Salt softens water in a process called ion exchange. Water hardness minerals are exchanged with sodium ions, eliminating the effects of hard water.

What is the difference between regular salt and water softener salt?

The difference between regular salt and water softener salt is this: water softener salt is unsuitable for cooking and seasoning purposes because it isn’t adequately cleaned and often contains dirt and other impurities, while regular table salt is pure sodium chloride and iodine and is properly cleaned and processed for cooking purposes.

Does water softener salt have chemicals?

Some water softener salt contains chemicals or impurities that reduce iron fouling in the resin and enhance the salt’s softening abilities. However, many salt brands sell chemical-free salt products for customers that want an all-natural solution.

Can you drink water that has water softener salt?

Yes, you can drink water that has been softened with salt. Salt-softened water contains only a tiny amount of salt that shouldn’t take your sodium intake over the edge. You shouldn’t notice that your soft water has a salty taste.

Related: Can you have an allergic reaction to water softener salt?

Is salt water considered hard water?

No, salt water isn’t hard water. In fact, salt is used to soften water, so salt water isn’t considered hard at all – it’s considered soft. Hard water is water that contains calcium and magnesium minerals, which leave scale deposits on surfaces.

  • Jennifer Byrd
    Water Treatment Specialist

    For 20+ years, Jennifer has championed clean water. From navigating operations to leading sales, she's tackled diverse industry challenges. Now, at Redbird Water, she crafts personalized solutions for homes, businesses, and factories. A past Chamber President and industry advocate, Jennifer leverages her expertise in cutting-edge filtration and custom design to transform water concerns into crystal-clear solutions.

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