How to Clean an RO Membrane Using Vinegar | Guide
Written by: Alexandra Uta // Last Updated: Mar 23, 2023
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If the idea of cleaning your RO membrane with chemicals gives you the ‘ick,’ then good news! You can go the natural route and clean it with vinegar!
Cheap and effective, the acid in vinegar can break down various things that might foul your RO membrane.
So how do you go about cleaning? Let’s take you through the process.
Contents
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Key Takeaways
Here is how to clean an RO membrane using vinegar:
- Shut off the water supply to the system.
- Close the valve on the storage tank.
- Open the RO faucet. Wait till the water flow stops.
- Open the RO membrane housing and add vinegar to it.
- Screw the housing cap back on.
- Allow the membrane to soak in the vinegar.
- Flush the system for at least 30 minutes after the cleaning process.
How to Clean an RO Membrane Using Vinegar
Benefits: Why Is White Vinegar a Good RO Membrane Cleaner?
The primary acid in vinegar is called acetic acid, which can break down limescale, dirt, iron, manganese, and other elements that might scum up your RO membrane. A good soak in vinegar should increase the production capacity of the membrane, plus you will be:
- Saving money by not having to purchase specialized cleaning chemicals or solutions.
- Ensuring you are cleaning with natural products that cannot harm your health.
The downside? Vinegar is effective at removing scum but is not a good disinfectant.
Step by Step Instructions
Before you start, it is essential to check your reverse osmosis membrane’s specifications to ensure the material is okay with the low pH of vinegar. If it isn’t, then you can add water to the mix.
- Shut off the feed water supply to the system and close the storage tank valve.
- Open the RO faucet to drain the water and depressurize the system. When the water flow stops, close the faucet.
- Disconnect the RO membrane housing from the system.
- Open the housing and add vinegar to it.
- Screw the housing cap back on.
- Let the membrane soak in the vinegar that is now in the housing.
After this, you will need to flush the system by using your installed flushing kit or by disconnecting the flow restrictor if you do not have a flush kit installed. The length of time you need to flush for depends on your specific system and membrane, so check with the manufacturer.
Flushing with a flush kit:
- Locate the flush kit. It should be hooked up to the wastewater line at the back of the RO system.
- Position the ball valve so that it is aligned with the wastewater line. This means it is in flush mode.
- Run the system for at least 30 minutes.
Flushing without a flush kit:
- Disconnect the wastewater line from the system.
- Remove the flow restrictor from the wastewater line.
- Reattach the wastewater line.
- Run the system for about 30 minutes.
- Shut off the entire system again.
- Disconnect the wastewater line, reinstall the flow restrictor, and hook everything back up.
How Often to Clean a Reverse Osmosis Membrane
An RO membrane will last 2-5 years under good feed water conditions, so you probably won’t have to clean your membrane at all within that time if you have a point-of-use system. However, it should be cleaned if anything compromises the membrane, such as too many TDS in the water or excessive fouling.
Whole house reverse osmosis systems usually have different feed water conditions and may need to be cleaned 2-4 times yearly.
Further Reading:
Other RO Membrane Cleaning Methods
Especially in commercial or industrial applications, there are some other ways to clean an RO membrane, such as using chemical solutions or water pressure to forward or backflush the system.
Cleaning Chemicals
Chemicals are specialized cleaning solution for RO membranes. Determining which one suits your particular membrane and system is crucial. Sometimes, even more than one type of chemical will be required.
Low pH
Low-pH cleaning solutions are recommended when you have high levels of inorganic foulants such as sulfate scale, metals, and carbonate.
High pH
High-pH cleaning solutions are best for organic foulants and biological fouling. The best way to decide which one you need is to test the water to see what foulants yours contains.
Forward, Backward, and Air Flushing
These chemical-free cleaning methods will remove fouling from the RO membrane. Forward flushing involves using the feed water and pressure to wash off foulants lodged on the membrane. Backflushing does the same thing but from the opposite side of the membrane (the filtered water side). Air flushing uses air bubbles in water on the feed side to create turbulence to ‘shake off’ any debris from the membrane.
If you have any questions about cleaning an RO membrane with vinegar please don’t hesitate to leave a comment below!
About the Author Alexandra Uta
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