The Best Type of Salt to Use in Your Water Softener

Refilling the salt in your salt-based water softener is a major part of its ongoing maintenance. These particular systems use a brine solution to wash away the hardness minerals and regenerate the sodium-charged resin beads – which are essential to the water softening process.

If you notice that the salt in your brine tank is running low, you’ll need to refill it as soon as possible. You will likely come across common types of water softener salts like crystals, salt pellets, and potassium chloride. But which one do you choose? Salt pellets or potassium chloride pellets? Solar or evaporated salt pellets?

To answer those questions, let’s look at each type of water softener salt and what situation each works best in.

Softener Salt or Softener Potassium Chloride: How Are They Different?

Ideally, water softeners work best with salts that are specially designed for softening water. That means no dicing, table salts or any salt of that kind.

Usually, when you want to change the salt in your water softener, you can choose from either sodium chloride (crystals, pellets and block salt) or potassium chloride.

The type of salt you use can affect the efficiency of your water softener and the regeneration process. It can also impact the amount of sodium that gets into your softened water, the cost of salt changes, and how often your brink tank needs to be cleaned.

Let’s now discuss each type of water softening salts in detail.

Sodium Chloride (Salt)

Salt pellets, crystals and block salt are the three different forms of sodium chloride. Apart from being readily available in a variety of forms, sodium chloride is widely used because of its lower cost and effectiveness.

Here’s a brief breakdown of the available options:

  • Salt Crystals:
  • Rock Salt: As the name suggests, rock salt resembles small rocks or pebbles. It is mined underground and forms when salt deposits accumulate. Rock salt is the rawest kind of salt on this list, which means that the salt crystals from the salt itself may contain other traces. Even though rock salt is more economical, it has a high amount of calcium sulfate, so it may not dissolve well in water and may lead to constant maintenance headaches. Literally.
  • Solar salt: Solar salt (more commonly known as ‘sea salt’) is a byproduct of evaporated seawater. It is naturally produced when the sun dries out the highly saline seawater. This type of salt is 99.6% pure. Also, it is highly soluble, even more than rock salt. That means it is able to dissolve much faster than other types of water softener salts. You can use it if your system suffers from frequent salt buildups, “mushing”, or “bridging”. Using this type of salt can help extend the life of your softener and lower the need for frequent maintenance.
  • Evaporated Salt Pellets (Our Top Pick): Evaporated salt is the purest form of sodium-based salts for softening water. And as you’d expect, it’s the most expensive type listed here. This type of salt forms when raw salt is converted to sodium chloride and all the moisture has been removed. What’s left from this process is 100% pure salt. Because of this pure state, evaporated salt pellets are highly effective at treating hard water and making it soft.  
  • Block Salt: Block salt is on the list of salts that are not ideal for water softeners. Some companies add a bonding agent to the salt to form the blocks, which is just more impurities being added to the salt. Therefore, we do not recommend using it.

Potassium Chloride

Potassium chloride is a great alternative to salt (sodium chloride), especially since it is 99.9% sodium-free. While this makes it perfect for those who are looking to reduce their sodium intake, the potassium is not healthy for people with hypertension or a history of this condition in their family. Also, potassium chloride pellets are usually more expensive and are not as accessible as salt pellets. 

If you are thinking about switching from salt to potassium chloride pellets, you might have to increase the salt dosage program setting on the valve by about 10% to make sure that the system regenerates properly.

How to Maintain Your Brine Tank: 3 Useful Tips

  1. Regularly check the salt level in your brine tank (at least every month). Once the salt in the brine tank falls below one-quarter full, you run the risk of not having softened/conditioned water.
  2. For optimal efficiency, keep the salt in the brine tank at least three or four inches above the water level, but no more than four inches below the top of the tank.
  3. Loosen any encrusted salt around the brine tank and ensure that the large blocks are broken up before added any new salt to it. Adding hot water to the salt blocks will help break them up.


Water softeners aren’t cheap. So, they must be maintained properly. Good maintenance involves refilling the brine tank with the right type of salt. Water softeners work well with sodium chloride or potassium chloride, but depending on your situation, you can use this guide to determine the type that is best for you.