Can I Put Bleach in My Water Softener?

By: Jake Gallagher | September 26, 2023

Simple answer, no, you really shouldn’t do this.

It’s generally not advisable to use bleach to clean a water softener. Bleach can damage the resin beads in the softener and reduce its effectiveness. Therefore, most water softener manufacturers do not recommend the use of bleach for cleaning or maintenance purposes.

However, there may be some situations where you could use a small amount of bleach to clean a water softener. 

Keep reading to find out what those circumstances are and how to do it safely.

Effects of Bleach on a Water Softener

Bleach is a strong oxidizing agent that can break down and damage the resin beads, which can reduce the effectiveness of your water softener in removing hard minerals from your water.

The extent of the damage will depend on the concentration of bleach, the amount of time it was left in the system, and the type and age of the resin beads. In some cases, the damage may be irreversible, and you may need to replace the resin beads or even the entire water softener system.

If you have accidentally added bleach to your water softener, contact a professional plumber or water treatment specialist to assess the damage and provide guidance on how to proceed. 

They may recommend flushing the system with clean water to remove any remaining bleach and then replacing the resin beads or other damaged components as needed.

How to Flush a Water Softener After Using Bleach

Flushing a water softener involves removing any accumulated sediment, minerals, or debris from the system. If you have cleaned your water softener using bleach, it’s important to flush the system thoroughly with clean water to remove any residual bleach and prevent damage to the resin beads.

Here are the general steps to flush a water softener that has been cleaned using bleach:

  1. Before beginning the flushing process, make sure to turn off the power to the water softener to prevent any damage to the electrical components.
  2. Use a bucket or hose to drain the brine tank completely.
  3. If the resin beads have been damaged by the bleach, they will need to be removed and discarded.
  4. Once the resin beads have been removed, clean the inside of the tank using a soft-bristled brush and clean water to remove any residual bleach.
  5. If the resin beads have been damaged or need to be replaced for any reason, install new beads according to the manufacturer’s instructions. Otherwise, put the original resin beads back in the tank.
  6. After the tank has been cleaned and the resin beads have been installed, fill the tank with clean water.
  7. Follow the manufacturer’s instructions to regenerate the system and ensure that it is functioning properly.
  8. Once the regeneration process is complete, flush the system with clean water for several cycles to remove any remaining bleach or sediment.
  9. After the system has been thoroughly flushed, turn the power back on to the water softener and monitor it closely to ensure it is functioning properly.

It’s important to follow the manufacturer’s instructions for your specific water softener model and seek the advice of a professional if you are unsure how to proceed.

Reasons to Use Bleach in a Water Softener

While it’s generally not recommended to use bleach to clean a water softener, there may be some limited circumstances where a small amount of unscented household bleach can be used to clean the system without causing damage to the resin beads. Here are some examples of when a small amount of bleach may be appropriate:

Removing organic matter

If your water softener has accumulated organic matter, such as algae or bacteria, a small amount of bleach may be effective in removing it. In this case, use a very small amount of bleach (less than 1/2 cup) and dilute it in a bucket of water before adding it to the system.

How to remove organic matter from a water softener with bleach:

  1. Turn off the water supply to the water softener and unplug the unit.
  2. Disconnect the brine tank and remove any remaining salt or brine solution.
  3. Mix a solution of 1 cup of household bleach per 1 gallon of water.
  4. Pour the bleach solution into the brine tank and allow it to sit for at least two hours.
  5. Reconnect the brine tank and turn on the water supply to the softener.
  6. Allow the water to run through the system for at least 20 minutes to flush out the bleach solution.
  7. Perform a manual regeneration cycle to ensure that the resin bed is properly cleaned.
  8. Repeat the flushing process until there is no longer any bleach smell or taste in the water.
  9. Refill the brine tank with fresh salt or brine solution and plug in the unit to flush out any residual bleach.

Again, it’s crucial to remember that using household bleach to clean a water softener system is not a recommended method and should only be done in rare situations. If you’re unsure, it’s best to get advice from the manufacturer or a professional plumber, or water treatment expert. 

Sanitizing a water softener

Sanitizing water softeners involves cleaning and disinfecting the system to remove any harmful bacteria, viruses, or other microorganisms that may be present. This is typically done by using a chemical disinfectant, such as chlorine bleach or hydrogen peroxide, to kill off any harmful microorganisms that may be present.

How to sanitize a water softener with bleach:

  1. Turn off the water supply to the water softener and unplug the unit from its power source.
  2. Drain the brine tank by removing the salt and any remaining water. Use a wet/dry vacuum to remove any remaining brine or debris from the bottom of the tank.
  3. Mix a sanitizing solution of bleach and water, using a ratio of one cup of bleach for every three gallons of water. Make enough solution to fill the brine tank at least halfway.
  4. Pour the sanitizing solution into the brine tank and allow it to sit for at least two hours. For heavily fouled systems, a longer dwell time of up to six to eight hours may be required.
  5. After the sanitizing solution has been in the tank for the appropriate amount of time, open a cold water tap near the water softener and let the water run for several minutes to flush the system. This will help to remove any residual disinfectant and contaminants.
  6. Allow the system to run through several regeneration cycles to ensure that any remaining disinfectant is flushed from the system.
  7. Once the water softener has been thoroughly flushed, refill the brine tank with salt and add enough water to cover the salt.
  8. Plug the water softener back in and allow it to resume normal operation.

It is important to note that the specific steps for sanitizing a water softener may vary depending on the manufacturer’s recommendations and the specific type of system. 

How to run a water softener bleach cycle:

Some water softener manufacturers may recommend running a manual recharge cycle using a small amount of bleach to clean the system. If your water softener’s manufacturer suggests you run a bleach cycle, it will normally follow these steps in sequence:

  1. Remove the cover from the brine tank. Determine if you have a 9-inch or 12-inch brine tank by measuring across the top.
  2. Fill a 9-inch tank with one cup of bleach or a 12-inch tank with two cups of bleach. Place the cover on the brine tank.
  3. On the water softener, look for the cycle panel. Set the control module to perform a manual recharge cycle. This procedure is determined by the unit you own. If the procedure is not clearly shown on the module, see the owner’s manual for more details.
  4. Avoid drinking any water in the house until the full regeneration process has been finished.

It’s highly advisable that you use regular, unscented household bleach. Splash-proof bleach or bleach containing any additives should not be used. Do not mix bleach with red-out salts, salt with additives, any other resin bed cleaners, or any other common household cleaners.

Manually cleaning the brine tank

If you need to clean the brine tank in your water softener, a small amount of bleach may be effective in removing buildup and grime. However, it is important to use only a very small amount of bleach and to rinse the tank thoroughly with clean water to remove any residual bleach.

How to manually clean a water softener with bleach:

  1. Turn off the water supply to the water softener and unplug the unit from its power source.
  2. Locate the water softener resin tank and disconnect it from the system. Depending on the manufacturer, this may involve removing the tank from the system or simply disconnecting the inlet and outlet pipes.
  3. Mix a solution of bleach and water, using a ratio of one cup of bleach for every gallon of water. Make enough solution to completely fill the resin tank.
  4. Pour the bleach solution into the resin tank and allow it to sit for at least two to three hours. For heavily fouled systems, a longer dwell time of up to six to eight hours may be required.
  5. After the dwell time, open the drain valve on the bottom of the resin tank and let the bleach solution drain out completely. Be sure to dispose of the solution properly, following local regulations.
  6. Rinse the resin tank thoroughly with clean water, using a hose or bucket to flush out any remaining bleach or residue.
  7. Reconnect the resin tank to the system and turn the water supply back on.
  8. Allow the system to run through several regeneration cycles to ensure that any remaining bleach is flushed from the system.
  9. Once the water softener has been thoroughly flushed, refill the brine tank with salt and add enough water to cover the salt.
  10. Plug the water softener back in and allow it to resume normal operation.

Conclusion: What Is the Best Way to Clean a Water Softener?

Using a water softener cleanser is the best and safest way to clean a water softener. These cleansers are specifically designed for use with water softener systems and can effectively remove mineral buildup, iron deposits, and other contaminants that can reduce the efficiency and effectiveness of the softener. 

While bleach can be an effective way to sanitize and disinfect a water softener, it can also have negative consequences if not used properly. Unlike household bleach, which can be harsh and dangerous, water softener cleansers are formulated to be gentle and noncorrosive, making them a safer and more effective choice.

For more information on how to clean your water softener system, read this article. If you’re looking for more expert information about other household water treatment systems, see my article on the best water filters for every situation.

Want to delve into a more comprehensive approach to maintaining your softener? Feel free to peruse the additional resources we’ve included below.