How Does a Water Softener Brine Tank Work?

How Does a Water Softener Brine Tank Work?

Water softening is an essential process that helps to remove the hardness minerals from water and keeps your plumbing and appliances in good condition. One crucial component of a water softener system is the brine tank.

In this article, we’ll explore the parts of a water softener brine tank and how it works.

Read my article – Ultimate Guide to Water Softeners: Everything You Need to Know.

Understanding the Parts of a Water Softener

Before we delve into the specifics of a brine tank, it’s important to understand how a water softener system works. In brief, a water softener is a device that removes the hardness minerals, such as calcium and magnesium, from the water. These minerals cause scaling and clogging of pipes and appliances, reducing their lifespan.

A water softener has two tanks: the media tank and the brine tank. The media tank contains a bed of resin beads that attract and trap the hardness minerals from the water. The brine tank, on the other hand, contains a solution of salt and water that regenerates the resin beads, flushing out the trapped minerals and replacing them with sodium ions.

What Does the Water Softener Brine Tank Do?

A water softener brine tank plays a critical role in the water softening process. It is where the sodium ions – which are necessary for regenerating the media – are generated. It holds a concentrated solution of salt and water, known as brine, which is used to recharge the water softener’s resin bed.

The resin bed is where the ion exchange process takes place. When hard water passes through the resin bed, the calcium and magnesium ions are exchanged for sodium ions, effectively softening the water.

During the water softening process, the brine tank periodically fills with water to regenerate the resin bed. The regeneration process involves flushing the resin bed with brine, which removes the accumulated calcium and magnesium ions and replaces them with sodium ions.

This process is essential for maintaining the effectiveness of the water softener and ensuring that it continues to remove hardness minerals from your water.

The following table summarizes the main functions of the water softener brine tank.

Stores SaltThe brine tank stores the salt that is used to regenerate the resin beads in the water softener.
Mixes Salt and WaterThe salt in the brine tank is mixed with water to create a brine solution.
Regenerates Resin BeadsThe brine solution is used to regenerate the resin beads in the water softener.
Flushes Out Hard MineralsThe brine solution flushes out hard minerals from the resin beads, which are then replaced with sodium ions.
Controls Water LevelThe float valve in the brine tank controls the water level and ensures that the brine solution is at the right concentration.

Related articles:
Is Your Water Softener Using Too Much Salt? Learn How to Fix It Now!
Water Softener Salt: Everything You Need to Know

Parts of a Brine Tank

The brine tank is where the salt and water solution is stored for the water softener system. The tank usually has a capacity of 150 to 300 pounds of salt, depending on the size of the water softener.


Inside the brine tank, there is a 3/8 inch tubing that connects to the brine well, which is the white part in the tank. The brine well has a cap on top, which is called the brine well cap. Inside the brine well, there is a float that determines the amount of water in the tank.

Float assembly

The float is a crucial part of the brine tank. When the water softener is in the brine cycle, the float assembly allows water to flow from the top of the float and into the tank. As the tank fills with water, the float rises and shuts off the water supply when the tank is full. When the water softener is in the regeneration cycle, the float assembly allows the brine solution to flow out of the tank and into the media tank.

Other components

Other parts of the float assembly include the float part, which determines the maximum water level in the brine tank, and the shutoff valve, which stops the water flow when the float reaches its maximum height.

The spigot on the outside of the brine tank is not typically connected to anything. It is just there as a drain in case you need to empty the brine tank for any reason.

One-Piece vs. Two-Piece Water Softeners

Not all water softeners are the same. Some water softeners are one-piece, while others are two-piece. In a one-piece water softener, the brine tank and media tank are combined in one tank. In a two-piece water softener, the brine tank is a separate tank from the media tank. For example, the Water Boss or AquaMaster water softeners have the brine tank on the outside and the media tank on the inside.

Cleaning Your Brine Tank

Cleaning your brine tank is an important part of maintaining your water softener system. Over time, the brine tank can develop a buildup of salt and other minerals, which can affect its performance.

To clean your brine tank, you will need to first turn off the water supply to the water softener system. Then, empty the brine tank completely of any remaining salt or brine solution.

Next, mix a solution of warm water and dish soap in a bucket. Use a scrub brush or sponge to clean the inside of the tank thoroughly, removing any buildup or residue. Rinse the tank thoroughly with clean water and dry it completely before refilling it with salt and water.

It’s important to note that you should never use harsh chemicals or abrasive cleaners to clean your brine tank, as they can damage the tank and affect the performance of your water softener system.

Regularly cleaning your brine tank can help ensure that it functions properly and helps to keep your water softener system working efficiently. It’s recommended to clean your brine tank at least once a year or more frequently if you notice any buildup or issues with the system.


How does my brine tank know how much water should be in it?

Your brine tank uses a float system to regulate the water level. The float rises and falls with the water level, signaling the water softener when to add more water to the tank.

Does my salt tank need to be full of salt all of the time?

No, your salt tank does not need to be full of salt all of the time. You should keep the salt level above the water level but don’t overfill it.

How much salt needs to be in my salt tank for it to work?

You should fill your salt tank at least halfway with salt to ensure that the water softener has enough salt to make brine. But, it’s important not to overfill the tank.

Will my brine tank still work when there is no salt in it?

No, your brine tank will not work when there is no salt in it. The salt is what makes the brine solution that helps regenerate the resin bed.

Does a brine float need to be maintained?

Yes, you should check and maintain your brine float on a regular basis to ensure it’s working properly. Over time, the float assembly can become clogged with debris or mineral buildup, which can affect its function.

Does a water softener brine tank need to be replaced?

A water softener brine tank is designed to last for many years with proper care and maintenance. However, there may come a time when it needs to be replaced. Some signs that your brine tank may need to be replaced include cracks or leaks in the tank, a malfunctioning float, or the tank is not holding the right amount of salt or water. If you are experiencing any of these issues, it may be time to consider replacing your brine tank. It is best to consult with a professional water treatment specialist to determine if a replacement is necessary.


A water softener brine tank is a crucial component of a water softener system. It stores the salt and water solution that regenerates the resin beads in the media tank. Understanding how the brine tank works will help you maintain your water softener system and keep your water free of hardness minerals.

Boch Richard

Richard Boch is a chemical engineer responsible for designing water filtration systems for industrial and residential customers. He has more than 20 years of experience with ion exchange, activated carbon, and reverse osmosis. Richard's expertise has made him a go-to source for municipalities and businesses looking to improve their water quality. When he's not working, Richard enjoys spending time with his wife and two young children.

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