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Water Softener Salt Facts: All You Need to Know

by Carl Jensen

Plumber, Welder, Contractor

> 2 min read

Water Softener Salt Facts: All You Need to Know

Many consumers use a water softener to remove excess minerals such as magnesium and calcium from the water supply. While purchasing a high-quality water softener is an excellent first step, you can optimize its performance using the right kind of salt. 

Water softener salt is used to regenerate the resin beads in an ion exchange unit, so you need to keep a sufficient supply in your water softener, or it can not perform its job effectively. It’s also important to know how to keep your water softener salt from turning to sludge in your brine tank, potentially clogging the system. 

Fortunately, it doesn’t take long to learn everything you need to know about water softener salt.

Why Water Softener Salt is Important?

Your water softener removes magnesium and calcium in a resin tank, turning hard water into soft water. The process occurs when positively-charged magnesium and calcium ions come into contact with resin beads. These beads have a covering of negatively-charged sodium ions, which comes from your salt supply. 

The magnesium and calcium ions stick to the beads, which release the sodium ions into the water supply. Sodium does not have the same harmful effects as magnesium and calcium, making it a safer addition to your water. 

However, as the beads continue to release sodium ions over an extended period, the sodium supply runs low. You need to recharge the beads with sodium ions by adding more salt. If you allow the salt supply to run out, the beads cannot perform the ion exchange process, leaving your home susceptible to hard water damage.

How Much Water Softener Salt Should I Use?

The water softener manufacturer instruction booklet will state the optimum salt level. However, the amount you need to use depends on your area’s hard water mineral concentration, how much water you use, and your water softening system’s performance. 

It’s good practice to check your salt level at least once a month and top up the supply when it falls below the recommended level.

"Sodium does not have the same harmful effects as magnesium and calcium, making it a safer addition to your water." 

Are There Different Types of Water Softener Salt?

You can purchase different types of salt, and some perform better than others. Some kinds of salt contain impurities that hinder performance, while others may clog your brine tank. There are several popular types of water softener salt to consider.

Block Salt

Block salt is the most affordable salt type and is also used for cooking. It is easy to load the blocks into your water softener, but the product’s high contaminant levels often counterbalance this advantage.

You need to submerge the blocks underwater wholly, and you may need a professional to ensure you have the correct water setting to cover the salt.

Sea Salt

Sea salt is also known as solar salt. Manufacturers fill a pond with salty seawater and expose it to sunlight and wind. Contact with these elements increases salt concentration until there is a solid block of salt crystals. 

Sea salt is relatively inexpensive, but the product quality can vary. There may be impurities that could lower the water softener performance level.

Rock Salt

Manufacturers obtain rock salt from underground deposits, increasing the potential for impurities in the product. The mining sites may not be clean, allowing other minerals to combine with the salt. These harmful mixtures can clog your brine tank and result in salt bridges which can be challenging to remove. 

However, rock salt is widely available and comes with a more affordable price tag than other salt types.

Potassium Chloride

Although it is unlikely the sodium levels in a water supply would cause harm to human health unless you have a specific ailment, you don’t have to use sodium-based salt in your water softener. Potassium chloride pellets are an excellent option for consumers concerned about their sodium intake.

The main disadvantage of using potassium chloride is that it conditions water rather than using ion exchange to remove calcium and magnesium. This type of salt prevents hard water from damaging your pipework, but the harmful minerals are still present in the water supply. 

Potassium chloride is one of the more expensive options, and because it isn’t as effective as sodium, it may not be the right choice for many consumers.

Evaporated Salt

Evaporated water softener salt has been through a distillation process, producing nearly 100% pure salt. Because of the absence of impurities, evaporated salt performs more effectively than many alternatives. You can benefit from less maintenance because this salt type doesn’t clog your brine tank.

Your water softener may last longer because it operates efficiently. However, there is the disadvantage that evaporated salt tends to be more expensive.

How to Clean Salt from Your Water Softener?

Many modern salt water softeners can operate for long periods without cleaning. However, you can increase your water softener’s operational efficiency and lifespan by ensuring there is no salt build-up. 

When salt clogs a water softener, it results in decreased performance. By turning off the water supply and emptying the remaining salt from your brine tank regularly, you can keep your unit clean. 

You may notice salt bridges (a salty crust that creates a gap between the salt and the water) and a sludge-like substance if salt has been present in your brine tank for a long time. You can quickly remove these blockages by pouring warm water over the salt and loosening the substance with a broom handle.

Water softener salt dissolves easily when you apply a regular household cleaner, and you can refill your tank to the recommended salt level. It isn’t difficult to clean salt out of your brine tank, but you should aim to perform the process approximately every three months to prevent clogging.

The Bottom Line

Deciding which water softener salt comes down to your personal preferences and goals. If you aim to lower sodium consumption, potassium chloride is a great choice. However, for optimal performance, evaporated salt is the leading contender. 

You can ask your municipality about the hardness of your water to make a more informed decision. If the magnesium and calcium levels are relatively low, perhaps a cheaper salt type is sufficient for your needs.

Carl Jensen

About the Author

Carl Jensen is a plumber with over 50 years of experience in the industry, as well as related jobs like underwater welding. He runs a successful plumbing practice in Tampa, Florida, and contributes his plumbing expertise to our DIY articles, and helps to fact check and consult on most of our other stuff to boot.