Your Guide to Water Softener Salt

In general, the average water softener needs a regular supply of salt to function at its best.

As hard water minerals pass through your water softener, any calcium and magnesium lingering in the water will cling to the resin beads in your mineral tank. When you flush a sodium brine through your tank, the sodium ions drive away the calcium and magnesium from the beads. Soon, you can enjoy softer water while the harder minerals simply wash down your drain.

However, different types of salts perform better than others. Some types contain impurities that clog up the tank while others dissolve poorly and reduce your unit’s efficiency.

To find out which salts work best, take a look at the most common water softener salts below.

1. Pellet Grade Salt

Pellet grade salt, or evaporated salt pellets, has one of the highest purity levels available. To create pellet salt, manufacturers dissolve the salt in its raw state, then use heat to extract all the moisture. As a result, the remaining salt is approximately 99.9% pure.

Due to the purification process, pellet grade salt is one of the most expensive salts you can purchase for your water softener. However, its purity also means that you’ll see much less buildup on the bottom of your tank, and your softener will undergo less corrosion.

2. Solar Pellet Salt

Solar pellet salt, or sea salt, comes from evaporated sea water. To create solar salt, sea water washes into salt evaporation ponds, or salt pans, which allow the water to naturally evaporate. Manufacturers then harvest the remaining sun-dried crystals and ship them around the world.

Sea salt contains a lot of impurities, which give the salt a variety of colors, from blinding white to pale grey to a soft pink. These salts are more water soluble than pellet salt, so sea salt might not work as well as pellet salt when you have a high water hardness level. If you have a fairly soft water already, you can use pellet salt and solar salt interchangeably.

3. Rock Salt

Rock salt, or halite, is technically a rock rather than a mineral. Experts mine the salt from deposits via machines similar to pneumatic drills. Once mined, the salt lumps ship to a crushing and screening plant, where they are broken into smaller, more manageable pieces. Often, manufacturers treat rock salt with an anti-caking agent to keep the salt from coagulating in the package.

Although rock salt represents an affordable way to de-ice your sidewalk and driveway, it’s not the best option for your water softener. Rock salt has a great deal of impurities, more than solar pellet salt. These impurities quickly cake to your unit, and you’ll need to regularly clean the brine tank to ensure your softener’s optimum performance.

Furthermore, rock salt tends to contain calcium sulfate, which means it won’t dissolve well in water and it will have a harder time removing calcium deposits already in your plumbing.

4. Block Salt

Block salt is a food-grade salt most commonly used in cooking and curing. As the name implies, block salt comes in convenient, compact, easy-to-load blocks that you can slide into your water softener. This is the cheapest kind of salt you can buy for your machine.

But before you assume that salt good enough for cooking is good enough for your unit, keep in mind that this salt has too many impurities to use reliably in your plumbing. Furthermore, your water softener needs to have high-enough water levels that the blocks remain completely submerged. If you have a water softener that accepts block salt, you’ll need to hire a professional to ensure the water levels are set to an appropriate level.

Not Sure Which to Choose?

All of the above salts have their pros and cons, so you may struggle to choose the right type for your unit. If you don’t know what salt type will work best for your budget or your water softener, talk to a water softener technician for additional help and advice.