Water softener salt changes are part of the ongoing maintenance required by any salt-based water softening system. Salt-based water softeners use a brine solution to wash away hardness minerals and to regenerate the sodium charged resin beads responsible for the softening process.
If the softener salt in your brine tank is running low, it’s time to pick up some more, and if it’s your first time changing salt in your water softeners, you may be taken aback by the many choices available: solar, pellets, potassium chloride pellets, etc. So, naturally, you might wonder what type of water softening salt should you get?
Here we discuss the most common softening salt options you may come across and some of their pros and cons, but first let’s take a look at what water softening really is.
How Does Water Softening Work?
Water softening relies on an ion exchange process that exchanges calcium and magnesium ions for sodium ions, thus, completely eliminating water hardness. The exchange happens with the help of sodium charged resin beads.
The ion exchange process that is at the heart of a water softener exhausts the resin as it becomes saturated with hardness ions. The sodium solution releases these ions, flushes them to drain, and resupplies the resin with sodium so it can be further exchanged for magnesium and calcium ions.
Unlike water softeners, limescale inhibitors or scale control systems don’t soften water, they just prevent the formation of scale deposits. These systems don’t use salt and are often referred to as non-salt water softeners, which is a misnomer as they don’t actually soften water.
For a distinction between salt-based water softeners and non-salt water softeners, read: Salt-Based vs Non-Salt Water Softener
How Often Should You Change the Salt in Your Softener?
Salt is used by your softener every time it regenerates. So, the more it needs to regenerate, the more salt it uses. Usually, metered water softeners regenerate only when necessary, so they use less salt (and less water) than clocked systems, which are programmed to regenerate at certain intervals.
As a general rule of thumb, it’s a good idea to check your water softener at least one a month. For a constant supply of soft water, keep the tank half-full of salt. Don’t overfill the tank!
Every time you add salt to the brine tank, break up any large pieces of salt and loosen salt that may be adhering to the perimeter of the tank.
What Type of Softener Salt Should You Get?
Usually, when you want to change the salt in your water softener you can choose from
- salt pellets;
- salt crystals; and
- potassium chloride.
The type of salt you use can impact how effectively your water softener regenerates, how much sodium ends up in your softened water, the salt change costs, and how often you have to clean your brine tank.
Salt crystals are available in two variations – rock salt and solar salt. Rock salt is the least expensive of all softener salts, and it’s mined from the ground as any other mineral. While it’s cheap, it’s also the softener salt that contains the most amount of impurities, which can increase salt bridging and lead to accumulation of debris, which means you’ll have to clean the brine tank more often (about 2-3 times a year).
Solar salt is obtained through the evaporation of naturally occurring brine (e.g. sea water). It presents a higher purity than rock salt but is not as pure as evaporated salt. With heavy salt usage, insoluble substances tend to build up faster, which in turn leads to more frequent brine tank cleaning.
While some solar salt brands may contain 99.6 % pure salt, salt pellets contain 99.9% sodium chloride, making it one of the purest water softeners salts available. Evaporated salt pellets are created by forcing water into naturally occurring salt deposits, then pumping brine water to the surface and exposing it to heat and vacuum evaporation.
Since salt pellets contain very little insoluble matter, they are the most expensive, but they significantly cut down on tank cleaning since bridging or mushing is virtually eliminated. This is the main reason why salt pellets are preferred in water softening applications.
Both salt crystals and salt pellets are the sodium chloride we are all familiar with, and that we all use to season food. Potassium chloride, however, is marketed as an alternative to sodium chloride for those who don’t want any sodium ending up in their water. Potassium chloride is 99.9% sodium-free. Thus, those on a sodium-restricted diet will prefer this type of softening salt.
The main disadvantage of potassium chloride is that it’s much more expensive than the other softening alternatives and less proficient at regenerating resin beads. To achieve nearly the same effects in regeneration offered by other salts, it’s recommended that you increase potassium chloride dosage by about 10%.
With all other salts, your water will end up containing some level of sodium (around 50 mg/litre). Even if sodium levels in your tap water won’t increase to alarming rates (50 mg/litre is considered a low sodium product). You can remove this sodium along with hundreds of other contaminants by installing a reverse osmosis water filter.
As you can see, of all the salt options available, salt pellets are the most efficient at regenerating resin beads and the least likely to form bridging. Spending a little more upfront for high quality salt pellets will result in less maintenance and cleaning issues.
Can You Use Different Kinds of Salts in Your Softener?
Generally, it’s not harmful to mix different kinds of salts in your water softener, but it’s best not to do it. Some water softeners will work with any type of salt, others may not.
For example, using rock salt in cabinet water softener models should be avoided because rock salt will most certainly lead to bridging and accumulation of water-insoluble matter, which can cause issues especially that cabinet models are more difficult to clean.
If you want to change the type of salt you’re using, it’s best to allow your unit to go empty or nearly empty of the type of salt you’re currently using, and only then add the new salt.
Brine Tank Cleaning
Besides salt changes, cleaning the brine tank can also be part of the maintenance routine associated with water softeners. An annual inspection of the brine tank is desirable, but not mandatory unless you’re using salt that is high in water-insoluble matter (e.g. rock salt).
If you’re using high purity water softener salt, brine tank cleaning is usually something you won’t have to worry about.
In case of bridging, you will have to manually break up the salt. Adding hot water can help the process of dissolving these salt bridges. If you’re dealing with bridging issues too often, try limiting the amount of salt you add to the salt keeper in your tank, or switch to high-purity salt like salt pellets. Build-ups should also be broken down or cleaned to prevent softener malfunction.
Are There Alternatives to Salt-Based Water Softeners?
At the beginning of this article, we’ve mentioned that there is an important distinction between water softeners that use salt and non-salt water softeners.
Non-salt softeners are marketed as an alternative to traditional salt softeners, but they are in fact water conditioners or scale inhibitors, which means that they prevent limescale deposits, but without softening water.
Limescale inhibitors don’t remove hardness minerals from water, they just prevent them from sticking to surfaces. Thus, you can enjoy scale-free appliances and surfaces in your home, but not the other advantages that come with softened water.
Even so, limescale inhibitors present many advantages over traditional water softeners. Limescale filters are cheaper, they don’t use salt or waste water, they don’t come with a brine tank and backwash system, and other than replacing the filter, they don’t require any maintenance.
If softened water is not a requirement for you, scale control systems can be a viable alternative to water softening systems.
If your water softener works best with a certain type of softening salt, it’s usually best to keep on using that type of salt. If you want to try a different kind of salt, wait for your softener to go empty, before switching to a different kind.
Of all the salt options presented in this article, we find that evaporated salt pellets work best for most systems – they offer the highest purity, which leads to the most efficient regeneration, they don’t leave residue in your brine tank, and they don’t form salt bridges. Although they’re more expensive than other options, you also don’t have to worry about cleaning your brine tank several times a year.