How to Clean a Reverse Osmosis Membrane at Home

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Reverse Osmosis Membrane Cleaning

Even the best reverse osmosis system has to be well maintained to function properly. Only when a system is in good condition can it process water efficiently and remove its contaminants. One essential maintenance step is cleaning a system’s ro membrane, which is a reasonable alternative to cost-intensive replacements.

Membrane cleaning requires knowledge of when and how you have to clean and what chemicals you have to use. The right cleaner depends on the type of fouling/scaling the membrane has been exposed to.

In this blog post we are going to shed some light on those aspects and provide step-by-step instructions on how to clean your ro membrane at home.

When to Clean

Since it’s difficult to clean overly fouled reverse osmosis membranes and to prevent irreversible damage, it is crucial to stay on a strict schedule and clean them at an early stage of fouling.

day planner scheduleThe easiest way to find out when to clean is by monitoring water pressure before and after the system. If the differential pressure increases by more than 10%, it’s time to get active. The need for higher feed pressure to maintain water flow and decrease of flux are also clear indicators that your membrane needs to be looked after.

Of course cleaning frequency varies between different models from different manufacturers and also depends on the level of water contamination these are subjected to, but on average every ro membrane should be cleaned once about every 3 to 12 months. It is also helpful to take a look at the instructions provided or to get in touch with the manufacturer for further information.

How to Clean

The following instructions created by lead you through the process of cleaning an ro membrane. Please be aware that the necessary steps to clean a membrane without causing any damage to the system might vary from one manufacturer to another. This is especially the case for countertop systems.

By the way, we also have instructions on how to clean and sanitize an entire reverse osmosis system.

  1. Safety first! Always wear thick rubber gloves and protective eyewear when dealing with harsh cleaning chemicals.
  2. Turn off the system’s water supply.
  3. Turn off any water line going to a refrigerator or icemaker.
  4. Drain all water from the filter system and storage tank by opening the system’s water faucet.
  5. Close the faucet once all water has run out.
  6. Disconnect the membrane housing from the system and open it.
    • The best way to open up the housing is by using a strap wrench.
    • If you are also cleaning your filters, make sure to disconnect the membrane first, because cleaners such as bleach will destroy the membrane.
  7. Drain all water out of the housing and take the membrane out of it.
  8. Clean the membrane using a chemical cleaner suggested by the manufacturer or a reverse osmosis chemical supplier and follow the given instructions precisely. Take into account dosage, temperature, pH-values and contact time guidelines.
    • As stated above, depending on the type of fouling/scaling the membrane has been exposed to, you need to use different cleaners. Common types are:
      • Calcium carbonate scale
      • Metal oxides deposits
      • Silica scale
      • Inorganic and organic colloidal deposits
      • (Natural) organic material like mold and fungi

A Note on Chemical Membrane Cleaners

You have the choice between generic cleaners and more expensive labels. Expensive cleaners are oftentimes easier to use and customer support is more reliable.

This becomes even more important when you have to use a number of different cleaners in the right sequence one after another. Improper use might make the degree of membrane contamination worse. Here is an example sequence:

  1. Remember to also clean the membrane housing by using a bottle brush and some regular dish washer detergent and bleach mixed with water.
  2. Dispose of all cleaning chemicals adequately.
  3. Rinse the membrane and the housing thoroughly before putting them back together.
  4. Re-install the housing back onto the system.
  5. Turn on the system’s cold water supply and check for leakages.
  6. Flush the system (close tank valve, open ro faucet) before refilling your water tank to remove chemical residues.
    • Water quality might take a few hours to get back where it used to be especially after pH cleanings.

Time to get Started

Start lineYou now have all the necessary information you need to clean the membrane of your reverse osmosis water filter system. You should be able to figure out how and when to clean and what chemicals to use in which sequence.

Remember: It is essential to follow the manufacturer’s specifications precisely to not cause any damage to your system. If you are unsure about your next step, seek professional assistance to avoid mistakes.

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Leave a Reply 4 comments

Bruce - December 18, 2019 Reply

You have provided a very good summary, however I feel one area is lacking. Specifically, how do you flush the membrane? The actual mechanics. Following your instructions you remove the membrane, “then you flush”, then reinstall flush and check for leaks. I’m confused as to how is the flush process accomplished? When a system is assembled and working, water pressure flows in to the membrane, purified water flows out one outlet and wastewater drains to waste. But once I have taken the RO filter out of its housing I no longer have water pressure to flush cleaning solutions through the filter. And unlike conventional precipitate filters, which can be scrubbed from the outside to somewhat remove contaminants, the RO filter is a sealed unit and the membrane is not accessible from outside the unit. So please describe the method used for the actual cleaning and flush process.
Many thanks for your post which contains very valuable information.

    Derek - January 6, 2020 Reply

    I’ve edited the article. The instructions should be better to understand now.

Paul - December 26, 2019 Reply

“Instructions for how to clean your membrane: Read the manual that came with the cleaner. The end”.
Mine doesn’t have instructions.

    Derek - January 6, 2020 Reply

    We can’t give you general instructions. It all depends on the specific cleaner. You mix it with water and soak the membrane for a certain time. Then you rinse carefully.

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