How to Clean Your Reverse Osmosis System (Everything You Need to Know)

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Reverse osmosis systems are highly effective and fairly low-maintenance, but that doesn’t mean you can install one and ignore it. Most quality ro filters are expensive, so it’s best to maintain your system properly to maximize performance and longevity.

To prevent scale build-up and eliminate unhealthy bacterial growth, all that’s required is an occasional cleaning. While you can call out a professional to do it for you, it’s easy to sanitize a reverse osmosis system yourself by following this handy tutorial!

How to Clean and Sanitize a Reverse Osmosis System

A Few Tips Before You Begin

Keep in mind that it’s not strictly mandatory to sanitize reverse osmosis systems. If your home’s water supply is fairly clean and not especially hard, it’s possible you’ll not run into issues. That said, since it’s such an easy process, why not do it anyway just in case?

In most cases, we recommend cleaning all reverse osmosis systems annually to prevent scale, clogs, and the growth of pathogens which could compromise permeate quality. If the water feeding your system is particularly poor in condition, up the frequency to twice per year. Even then, it requires very little time and effort. Whenever you change one of the filter elements is a perfect time to get the job done.

The following instructions can be used as a general guide, but always check your system’s manual for customized guidance. You’ll also need to replace the post-filter after you complete this process.

1. Before you start, wash your hands. This will prevent any bacteria on your skin from contaminating the system as you work.
2. Fill a bucket with warm water and dish soap. Keep a sanitizing solution on hand for later use. Bleach or hydrogen peroxide will do the trick.
3. Shut off the water supply.
4. If any appliances are connected to the unit, like refrigerators or dishwashers, disconnect them before proceeding.
5. Open any faucets fed by the ro system, allowing them to empty fully. This will depressurize the system to prepare it for the next step.
6. Take out all the contents of the filter (reverse osmosis membrane + any pre-filters).
7. Using the warm, soapy water and a sponge, clean out the empty filter housings. Rinse with clean, cold water when you’re finished.
8. Now it’s time to get sanitizing. Pour two to three tablespoons of your chosen cleaning agent into the first filter housing. After checking that all the O-rings are in good condition and properly seated, screw the just-washed housings back together.
9. What’s left inside now? There should be nothing remaining but the cleaning agent and the post-filter. If that’s the case for you, you’re ready to turn the water back on.
10. Turn on the ro water faucet until water starts flowing. Then examine the system for any leaks.
11. Allow the tank to fill up, waiting up to two hours for the bleach to do its work.
12. Flush the tank fully not once, but two times. At this point, there should be no more sanitizer odor. If there is, flush the tank again.
13. Now the system is clean, but you’re not quite done! Turn off the water supply and depressurize the system one more time.
14. Reinstall the old filter elements that are still in optimal condition and replace any that are looking shabby.
15. Replace the post-filter.
16. Turn the water back on. Open the faucet to flush the system for approximately 2 minutes or until the faucet has stopped sputtering. If you notice any leaks, tighten any filter housings and try again.
17. Turn off the faucet and the tank should fill. But wait! Before you start drinking the water again, empty two full tanks as part of the replacement filter priming procedure.
18. Last but not least, reconnect all appliances.

Next, Clean the RO Membrane

While you wait for the tank to fill (step 11. from above), clean the filter components. In particular, pay attention to the semipermeable ro membrane. It accumulates debris over time, so either soak and rinse it, or replace it if it’s severely clogged. You can also do this step on its own.

Once again, the exact cleaning procedure will vary slightly from model to model, so refer to your owner’s manual for details. For general instructions, check this post: How to Clean a Reverse Osmosis Membrane at Home

The manual will also tell you what chemical solution can be used for your particular membrane and should describe how to dispose of it safely when the process is complete. When all is said and done, your ro membrane will be revitalized and ready for use.

Cleaning the RO Tank, Step-by-Step

Cleaning the ro tank itself is unnecessary if you’ve already sanitized the entire system, but if you’ve noticed an unpleasant, musty scent to your water, the tank may be the culprit. In that case, you can opt just to deep clean the storage tank.

1. The first step is, you guessed it, to shut off the water supply and turn on the faucet to depressurize the ro system.
2. Shut off the valve before the tank and remove the tank tube from the rest of the reverse osmosis system, leaving the other end still attached to the tank. Allow any water remaining in the tube to drain into a bucket.
3. Bypass any post-filter. Otherwise you will have to replace it after the cleaning procedure.
4. Carefully add ½ tablespoon of bleach or hydrogen peroxide to the tube. Using a funnel can help prevent spills.
5. Without allowing the bleach to spill out, reattach the tube to the ro system.
6. After checking that the ro faucet is off, open the tank valve and turn on the water supply. As usual, if there are any leaks, shut the water off, tighten all fittings, and try again.
7. Allow the tank to fill and give the bleach at least a half hour to kill off the bacteria. You can let the bleach sit for up to two hours to be on the safe side.
8. To finish the process, turn on the ro faucet until the tank is drained. Repeat, draining a second full tank of water. If there’s any lingering chemical scent to the water, flush one more tank of water before using it again.

That’s it! Now you know how to clean any and all elements of your reverse osmosis system to keep it in tip top shape. If you have any tips of your own or a question or two to clear up, comment below and we’ll be happy to help!