7 Water Softener Salt Types to Consider

When you go to the store to pick up water softener salt refills, are you just grabbing the first bag you see, or do you know exactly which type is best for your specific water softener? As it turns out, those bags of water softener salts aren’t all the same. They come in different formats, like pellets, blocks, or liquids, and some have more impurities than others. Read on to learn about different water softener salt types and determine which is right for your system.

1. Evaporated Salt

Evaporated salts are made through steam, turning the salt into a crystallized material that can then be produced into salt pellets, crystals, or cubes for your water softener. The evaporative process means this type of water softener salt is some of the purest you’ll find on the market at around 99.9% purity. However, this also means that it can come with a higher price tag. 

Because it has little to no impurities and dissolves quickly, evaporated salt is less likely to form stubborn salt bridges that can clog up the brine tank. It’s also great for homes with very hard water, or more than 180 milligrams per liter of calcium carbonate, according to the U.S. Geological Survey.

Best for: Households with very hard water

2. Solar Salt

When you imagine water softener salt, you’re probably thinking of solar salt, which is widely available and works with many water softener models. If you’re looking to strike a balance between a high-quality water softener salt and one that’s budget-friendly, solar salt could be just the compromise. Solar salt, available in water softener crystals or pellets, is made by using solar power to dry out seawater, leaving behind the salt. It’s not quite as pure as evaporated salt, but it does boast over 99% purity levels.

However, it has a lower solubility level than evaporated salt, meaning it’s not as quick to dissolve. This could cause the salt to clump and form salt bridges, especially in humid areas. Also, keep in mind that even the low level of impurities in solar salts can lead to staining around the brine tank or discolored water in the water softener, so be sure to clean the water softener and its tanks every year to every few years.

Best for: Homes with moderately hard water

3. Rock Salt

If you need to stick to a strict budget, you may consider rock salts, which are widely available and one of the lowest-cost options for water softener salts. When it comes to how often water softeners regenerate and require additional salt refills, it varies. Some models may regenerate multiple times per day, so homeowners can expect to refill the salt every six to eight weeks. That can really add up, so some homeowners may prefer to cut monthly or bimonthly costs by using rock salts.

But what you save in salt refills, you may spend in water softener repair costs. Rock salts are mined from underground, like evaporated salts, but they don’t go through much processing to remove any impurities. The higher levels of impurities, namely calcium sulfate, can cause clogs that wear out the water softener parts quicker.

Best for: Homeowners with time to handle more frequent maintenance

4. Block Salts

Boasting around a 99.8% purity level, block salts are a good value with low impurities at a low cost. With this type, the salt isn’t sold in pellets or crystals. Instead, it comes in a block form that sits in the brine tank. Because of the size of the salt block, you’ll need a larger brine tank that can accommodate the block and the higher water level you need to properly submerge the block. Only use block salt if your specific water softener user manual or a local water softener installation company recommends it.

The block will dissolve slowly, which means the brine won’t be as concentrated as it would with other water softener salt types, like evaporated salts. But the block form does help avoid salt bridges that can clog up the brine tank, and it helps reduce the amount of maintenance your water softener may need.

Best for: Specific water softener models as recommended by their manuals or a pro

5. Rust and Iron Removal Salts

Rust-removal or iron-removal salts are made with sodium bi-sulfate and are designed to prevent iron and rust from damaging your water softener and your pipes. If you have well water, which may have more iron than city water, you may want these types of salts to help prevent rust damage. 

Be sure to wear protective gear and closely follow the usage instructions for sodium bi-sulfate products because they can cause eye damage, skin irritation, and difficulty breathing.

While these products can help remove trace amounts of iron from hard water, if you have excess iron over the 0.3 milligrams per liter set by the U.S. Environmental Protection Agency, you’ll need to consider whole-house water filtration or purification systems to treat the water, not just iron-removal salts in your water softener.

Best for: Homes with well water

6. Potassium Chloride Salt Alternatives

Potassium chloride is a popular alternative to sodium chloride water softener salt. You can use potassium chloride in a water softener just like sodium chloride, meaning it will work with many water softener models. This is a popular alternative for people who may need to limit their salt intake, including through drinking softened water. It dissolves well in water, so you won’t need to worry much about clumps or clogs.

Potassium chloride does come at a higher cost than conventional salts. Potassium chloride costs $50 to $70 per 40-pound bag, compared to sodium chloride products that cost $5 to $10 per 40-pound bag. You’ll also need to use more potassium chloride to effectively treat the same amount of water as a smaller amount of sodium chloride.

Best for: People limiting their sodium intake

7. Specialty Cleaning Salts

If your water softener is prone to buildup or you’re just looking to cut down on cleaning and breaking up salt bridges, you may consider specialty cleaning salts. These are made with sodium chloride and additives that help keep the water softener and the resin clean.

You may need to order specialty cleaning salts through a water softener company or online, so they may not be as easy to source as standard salts. They also come at a higher cost, around $10 to $20 for 40 pounds.

Best for: Households with very hard water or well water