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Maintaining the salt in your brine tank is essential for the optimal performance of your salt-based water softener. After all, it’s the salt in the system that removes the hardness ions and softens your water. This makes choosing the right type of salt an important consideration.
With so many types of salt for water softeners on the market, including potassium alternatives, how do you know which is the right type? Here’s a break down of the types of salt for water softeners and their pros and cons.
Sodium vs. Potassium

Sodium chloride and potassium chloride are the two most commonly used types of salt for water softening devices. Both are natural minerals, are equally popular and do the same job effectively. However, there are differences in price, efficiency and availability.
Sodium Chloride
Sodium chloride is an affordable, easily available and effective option when used in water softeners. It’s lower in price compared to potassium salt, so if price is your priority, sodium chloride might be the better option.
Here are the main types of salt:
Rock Salt: Rock salt looks like small pebbles or rocks, hence the name. This type of salt is mined from underground naturally occurring salt deposits. This makes rock salt the most unprocessed and rawest type of salt. The trouble with rock salt is that it typically contains trace amounts of other elements, notably calcium sulfate. These reduce the solubility of the salt, which can result in maintenance issues in your water softening system. However, rock salt is the most affordable option, and may be suitable for small-volume systems as the insoluble materials may not be a big problem there. Our advice? Avoid this type of salt if you can.
Evaporated Salt – This type of salt is formed when rock salt converted to sodium chloride and allowed to dry. As moisture evaporates, what’s left behind is pure salt free of other trace minerals. This is the purest type of salt (100% purity) and the type we commonly use in cooking. Because evaporated salt is pure sodium chloride, it’s much more effective at removing mineral ions from water. However, it’s also the most expensive type of salt for your water softener. Even so, our advice is to opt for evaporated salt if you can.
Solar Salt – This is one of the more popular options, also known as sea-salt. Solar salt is made when sea water evaporates, leaving behind salt crystals. This type of salt dissolves easily and is highly effective at softening water. Solar salt is a good option for a water softening system as it doesn’t result in salt buildup and enhances the efficiency of the water softener. Solar salt is a highly pure salt variety and an excellent option for water softeners.
Sodium chloride comes in three main forms – pellets, crystals and cubes. These can be used interchangeably in most softeners, but always check the manufacturer’s instructions.
Potassium Chloride
Potassium is typically used in agriculture and, like sodium chloride, is a naturally occurring mineral. Potassium works in the same way that sodium does to soften water, but the only difference is that the hard water is replaced with potassium instead of sodium. Potassium is a vital nutrient and an excellent option for people who have sodium-related health issues, making it the preferred option for many people.
However, potassium chloride is more expensive than sodium chloride, sometimes up to 5 times as much, as extracting it from the earth is more costly. Also, potassium chloride for water softeners can be harder to access, as they aren’t as readily available. One more thing to note – when regenerating your resin tank, you may need up to 3 times as much potassium chloride as you would sodium chloride.
The bottom line when it comes to potassium chloride is that it’s much more expensive that sodium chloride, but it’s a healthier substitute.
Sodium Chloride or Potassium Chloride?
As we’ve discussed, there are several differences between these two types of salts, even though they do the same thing.
The most important considerations when deciding between the two will come down to budget and health.
- If you’re price-conscious and don’t mind the salt in your water, choose sodium chloride.
- If you’re on a sodium-restricted diet or are overall conscious about sodium intake, potassium chloride may be the better option.
Maintaining Your Salt-Based Water Softener

Salt-based softeners are much more effective than salt-free systems when it comes to treating hard water. These efficiently remove minerals from the water and take away the negative impacts of hard water on your home. Regardless of which salt you choose, it’s essential to maintain your water softener system to ensure that the system is functioning optimally.
Here are some ways to ensure that you get the most out of your water softening system:
- Always make sure there is enough salt in the brine tank. This is necessary for the resin tank to perform at its best capacity. If the salt levels drop, the resin tank’s ability to treat hard water will be reduced, resulting in untreated hard water entering your home again. Some water softeners come with a salt level indicator but most need to be manually checked. Simply lift the lid of the brine tank and check the amount of salt. If you can see the bottom of the brine tank or there’s a lot of water in the tank, it means that you may need to replenish the tank.
- Treat salt bridging if it occurs. Salt bridging refers to the crusting of salt crystals around on the tank, which happens when the maintenance hasn’t been top-notch. Bridging can reduce the capacity of the brine tank to hold the required amount of salt, so it’s best to remove these crusts by doing a tank clean up or simply loosening them and breaking large formations into smaller pieces. You can use hot water to help break up the large deposits. Add new salt only once you’ve treated bridging.
- Check if water has the right levels of salt. If your water feels too slick, you’re probably using too much salt, which produces too-soft water. Reduce the amount of salt your using and check the settings of the system to make sure its set at the correct setting for optimal salt usage.
- Water in the tank should be below salt levels. Brine tanks need salt to work, but always ensure that the water remains below the level of salt, so that its thoroughly mixed with the salt.
The Bottom Line
Because salt is at the heart of the salt-based water softening system, knowing about the types of salt and how to use it optimally will ensure that your system works to the best of its capacity.
From the different types of salt, choose potassium if you’re health-conscious and if price isn’t a big concern. However, choose sodium if you want a more affordable and readily available alterative.
If you’re looking to purchase salt for your softener, but aren’t sure which is the best type, we’ve covered this in our reviews of the best salt for water softeners. Additionally, to learn about the best water softening systems on the market, read our comprehensive guide here.