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Home » Water Softeners » What Happens If My Water Softener Runs Out of Salt?

What Happens If My Water Softener Runs Out of Salt?

By: Craig Smith
Last Updated:
What Happens If My Water Softener Runs Out of Salt?

If you have hard water coming into your home, then your water softener plays an important role in making your life easier.

That’s because it will help you avoid such situations as having to painstakingly scrub stubborn limescale off of your bathroom fixtures and have dishes and glasses with ugly water spots on them.

Not to mention hard water can cause clogged plumbing system pipes and create a whole host of other nuisance problems too such as iron staining. One of the only downsides to water softeners is that they require periodic maintenance.

One of the most important steps of which is making sure the salt level in the brine tank in the system is adequate. So, what happens if your water softener runs out of salt? That can be a problem for sure if your water softener can no longer remove hardness  minerals and I am about to tell you why.

I will also talk about steps you can take that will help you make sure that your water softener never runs out of salt and discuss how often you need to replace the salt in your water softener.

Can A Water Softener Run Without Salt?

SpringWell Salt Based Water Softener

The best way to answer this question is to talk a little about how salt based water softeners change the hard water coming into your home into the softer water that you like.

Your water softening system will consist of two tanks and a control head. Even if your water softener only appears to have a single tank, rest assured that it is a system that has two tanks encapsulated by a single shell. That’s because a salt-based water softener needs two tanks to function.

One tank is what’s known as a resin tank (mineral tank). It’s called this because inside the tank are special resin beads that are needed to make your water softener do its assigned function. The other tank is what’s called a brine tank. 

Traditional water softeners contain a brine mixture (salty water mix of either sodium chloride or potassium chloride).

The reason that your water softener can change hard water, which has minerals such as calcium and magnesium in it, into softened water is that inside of the water softener resin tank a process called ion exchange takes place.

Before your water softener can work, a brine solution is transferred into the resin tank (called the salt regeneration process). This salty water mix then coats the water softening resin beads inside of it very effectively.

This happens because the positively charged sodium chloride ions stick very well to the negatively charged resin beads. Now that your water softener is ready to do its job, the hard water flow from your incoming water supply then enters the tank that contains resin media.

Here it will encounter the now salt coated resin beads. Calcium and magnesium minerals contain positively charged ions that have a much stronger attraction to the resin beads than the salt ions they are currently coated with.

This causes the strongly positively charged calcium and magnesium minerals to displace the sodium ions on these special beads. This ‘ion exchange’ results in your water going from hard water to mineral-free softer water.

As you now know how the ion exchange process in your water softener works, you should be able to understand that without the salt needed to make the brine solution there is no way for the ion exchange reaction to take place in the resin tank.

When your water softener runs out of salt, you now have a water softener that no longer can perform its function. Even the best water softeners will not work without salt.

It would also not be a surprise if your water softener does run out of salt, so don’t be too hard on yourself if it does. That’s because there is very little in the way of operation and maintenance as far as your water softener is concerned that you have to do besides occasionally adding salt.

This fact about water softeners needing very little maintenance has lulled more than one water softener owner into complacency when it comes to periodically checking the sodium chloride level in their water softening system’s salt mix tank.

What Happens If a Water Softener Runs Out of Salt?


First of all, to ease your worries, if your water softener runs out of salt, you will not permanently damage it and it will still be able to eliminate hard minerals. However, it will then function very poorly (if there are some residual sodium ions still coating the resin beads) or not at all.

The only concern equipment-wise with your water softening system is that when hard water minerals pass through the system’s control head, they can build up over time and cause valves and other parts on the control head to malfunction.

There is also a small possibility that your salt mix tank may overflow because of sensors and brine float switches getting false signals that more water is needed in the brine tank to produce the salty brine mixture.

When your water softener is not working properly your soap and shampoo will not lather when taking a shower, your clothes will feel stiff after washing, your hair may start to get dryer, and your showerheads may clog up with limescale to the point that they need to be replaced.

This is because you are no longer supplying the resin tank with the brine mixture that it so badly needs to facilitate the ion exchange process that removes hard water-causing ions.

So, even though your incoming water will still pass through your water softener, hard water minerals are no longer being removed from it. It’s then the same as having no water softer at all.

You also must be aware that just adding more salt to your brine-containing tank after it runs out may not have an immediate impact on your water softener. That’s because it may take several regeneration cycles to get it functioning properly again.   

How To Ensure My Water Softener Doesn’t Run Out of Salt

Monitoring the salt level in your brine tank is the best way to make sure that your sodium chloride level in your water softener never gets too low or runs out completely. Here are 2 ways that you can tell it’s time to add salt:

  1. Manually Check the Salt level

Although this may be a little tedious and you might not always remember to do it, you can lift the lid on your water softener’s salt tank and simply check the salt amount inside of it.

You want to make sure that the tank is filled at least a third of the way with salt. My preference is to keep the salt level halfway up from the bottom of the tank. I also make sure that the salt in the tank sticks up above the water at least 2” to 4”.

The salt in your brine mix tank should also never be closer than 6” down from the top of the salt tank.

It’s also a good idea to set a reminder on your phone or keep track of your household maintenance checklist as to when it’s time to check the salt amount in your water softener.

  1. Buy a Water Softener with a Smart Control Valve

If you do not have the time or will to periodically check the salt level in your water softener’s brine tank, then I suggest that you purchase a water softener that has a smart control head. 

A water softeners control valve will take all of the work out of knowing when salt needs to be added to the brine mix tank.

That’s because they will alert you as to when it’s time to add water softener salt to the unit. Water softeners with smart control heads will cost you more but are generally worth it.

You must also be aware to not overcompensate by filling your brine tank higher than it’s supposed to be as mentioned above. Too much salt can be problematic for several reasons.

The most notable of which are such unwanted conditions in your salt tank as mushing, salt clumping on the walls of the tank, and a nuisance condition that’s known as a salt bridge.

Salt bridges form an unsupported layer of salt across the salt mix tank that will give the tank the appearance that it has more salt in it than it does.  

If any of these conditions appear because of excess salt in some water softeners brine mix tanks, then you will have to clean it out and add fresh salt to start from scratch.

Be careful when cleaning the brine tank because these tanks are known to have very thin walls and can be expensive to replace.

How Often Do You Need to Replace Salt in Your Water Softener?

This is a hard question to answer because of the differences between water softener brands and models. Here are some of the factors that go into determining how often you need to add more salt to your water softener:

  • The size of its brine tank
  • The amount of water usage in your household
  • The water hardness level of your incoming water
  • The quality of your water softener
  • The type of salt that you use
  • The age of your water softener, older models tend to have a lower salt efficiency

As a general rule, newer model water softeners usually only need to have salt added to them every 2 to 3 months. That means you only have to manually check a water softeners salt level about every 6-weeks.

Just remember a water softener that runs out of salt is like having no water softener at all, so make sure it never runs out of salt. 

No Salt, No Soft Water

While it’s true that your water softener requires very little in the way of maintenance, it’s also true that it’s not maintenance-free as far as adding salt to the system. Without salt, your water filter cannot perform its task.

So, make sure that you get used to manually checking the salt level in your water softener regularly or check for alerts from your smart controlled water softener that you need to add water softener salt to the brine mix tank.

This is not too tedious or time-consuming, especially considering how many benefits you and your family get because your hard water has been softened.Compared to other appliances, water softeners are not that hard to take care of. 

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Craig Smith
Craig got his start in water working in the swimming pool and spa industry. Water treatment would grow into his main career but he ended up working in the pool industry for over 26 years where much of his time was spent balancing the water in customer's swimming pools and installing water filtration equipment. Craig offers an abundance of water treatment knowledge after helping homeowners get pure water for 26 years.

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