How To Change Reverse Osmosis Filters?

Reverse Osmosis filters are a game changer. Thanks to RO filters, we can drink water that we know is pure.

A reverse osmosis filter can remove up to 99% of contaminants and harmful chemicals, which is why more and more people are investing in it. You’re looking at a long-lasting product with a reverse osmosis system.

Most reverse osmosis systems work for a long time, so people usually let the system run independently. But you can’t just leave a filter in the system for a long time, which is why you should know how to change reverse osmosis filters.

Changing reverse osmosis filters isn’t something you do as frequently as a conventional water filter, but it is always good to know how often to change reverse osmosis filters. Changing RO filters is easy, but the process and how often you need to change them vary according to your type of filter.

What Materials Make RO Filters?

RO filters use special membranes which separate the contaminants from the water. The membranes are made of semi-permeable (which only allows some things to pass) materials, which tightly wound together to prevent impurities from escaping.

The RO membranes are made from polypropylene (which has a plastic-like texture) and layers of polyester, polysulfone, and polyamide.

Types of RO Filters

Reverse Osmosis systems and filters vary depending on the filtration stages. An RO system typically has 4 stages, but newer RO filters also have a 5-stage and 6-stage structure. In older or simpler RO filters, you will find 3 stage structures.

How To Change Reverse Osmosis (RO) Filters (3)

3-Stage RO Filters

In a 3-stage RO filter, there are three primary stages through which water purifies. Each stage uses specific components to help clean the water.

  • In the first stage, a sediment filter separates contaminants like dirt, mold, and rust
  • In the second stage, an activated carbon filter removes chlorine, which can damage an RO membrane
  • In the third stage, an RO membrane filter removes other contaminants, including harmful substances like arsenic, lead, and copper

4-Stage RO Filters

In a 4-stage RO filter, an additional step eliminates the remaining contaminants.

  • The first three stages are the same as that of a 3-stage filter.
  • The fourth stage uses a Color Changing Resin Deionization Filter. The deionization filter ‘polishes’ the water, which means it attracts the contaminants in the water toward itself.

5-Stage RO Filters

In a 5-stage RO filter, the water goes through the same stages as a 4-stage one. An additional filter pushes water against a membrane while deionizing and polishing it to a greater extent.

6-Stage RO Filters

Following the first 5-stages, a sixth stage uses a mineralizer, which adds healthy minerals like magnesium to improve water quality and taste.

Which RO Filter is the Best?

A 3-stage RO filter is better than conventional filters, but some contaminants still remain in the water. A 4-stage and a 5-stage RO filter purifies and polishes water, eliminating all pollutants. A 6-stage RO filter adds minerals for enhanced flavors.

Ideally, a 6-stage RO system is best, but it can be costly compared to the rest. We recommend a 4-stage or a 5-stage filter for homes.

How to Change Reverse Osmosis Filters?

Changing RO filters isn’t a complex process, but it takes effort and time, which vary according to your stage filter. In all filters, it takes time to change the membranes since there is a particular process to handle them.

Additionally, with carbon block filters, you have to be very careful about when you’re replacing them. How often should carbon filters be changed depends on how much you’re using the filter. If the filters run continuously 24/7, you should replace carbon block filters between 18-20 months.

3-Stage RO Filter Change

To change a 3-stage filter, you’ll only need to untwist the canisters and clean them from the inside. For a 3-stage filter, a filter and an O-ring replacement are all you’ll need to do. It will take about 7-8 minutes per filter.

  • Using a filter wrench, twist the first canister to the left. Gradually open the canister into a bucket, as water will pour out of it.
  • After opening the canister, you will see a cylindrical filter inside. It may have changed colors from white to darker shades of black or brown. Take this filter out.
  • There will be a black rubber ring inside the canister. This is the O-ring. You’ll have to pry it out and replace it.
  • The canister will be muddy from the inside. Use soapy water and a soft rag to clean it from the inside.
  • After the canister is dry, attach a new O-ring and screw the new filter.
  • Repeat the process for the second and the third filter.

4-Stage RO Filter Change

You’ll find an additional filter for a 4-stage RO system on the central RO unit. A 4-stage RO system takes a minimum of 20 minutes to clean.

  • Follow steps 1-6 for the three filters below the central unit.
  • Detach the filter from the top of the central unit to make replacement easier
  • Remove the central hose (connected to the fatter/opening end of the fourth filter) without disconnecting the canister from the rest of the system. To remove the hose, hold down on the small tab on the top end of the opening end and pull the hose.
  • Open the canister using a filter wrench. You’ll see the membrane inside the canister.
  • Do not pull out the membrane using your hand or sharp tools. Instead, use a plier to gradually pull the membrane from the tiny space on its top.
  • You can use soapy water to rinse off the dirt inside the canister, but since you shouldn’t detach the canister from the primary source, you won’t have to.
  • Use a wrench to remove the new membrane and screw it inside the canister. Do not use your hands.
  • Screw back the canister’s lid, and tighten it using the wrench.
  • Reconnect the central hose and attach the filter back on the top.

5-Stage RO Filter Change

For a 5-stage RO filter, follow the same steps for the 4 filters. It will take a minimum of 30 minutes to clean the 5-stage RO system.

  • Follow steps 1-9 of the 4-stage filter.
  • Detach the old 5th filter, which will have a t-joint. Press down on the tab on the t-joint to remove the hose. Pull the other hose attached to the back of the filter the same way.
  • The new filter is wrapped in plastic. Do not remove the plastic yet; it is there for protection.
  • In 8-10 cups of water, add cup of bleach.
  • Rinse only the t-joint part of the filter in the bleach water, not the rest of the body. Use gloves for this step.
  • Let the tubed filter dry out. When it dries, peel off the plastic carefully.
  • At the ends of the filter where the hose will be attached, you’ll find small plastic cork-like pins, which will be blocking the holes. Pull out the pins.
  • Fix the ends of the hose inside the holes. Push the tube back in place.

6-Stage RO Filter Change

To change a 6-stage RO filter, follow the same procedure mentioned above. It will take a minimum of 40-50 minutes to change all filters in a 6-stage RO Filter system.

  • Repeat steps 1-8 given for the 5-stage filter system for the 6-stage filter change.
  • For the 6th tube, push down on the tab on the front end while simultaneously pulling out the hose.
  • Repeat step 2 for the hose on the other end of the tube
  • Open the tube/canister using a filter wrench and pull out the mineralizing filter. Change it with the new one and close the tube.
  • Connect the hose back to the tube and re-attach the tube to the central unit. 

Dos and Don’ts of Filter Changes

There are some precautions you have to take to ensure you don’t damage the filters or hurt yourself during the changing process.

  • Don’t change the filter when the water is on.
  • Do change the RO filters when recommended, instead of skipping the cleaning for months, even if you feel the water is clean.
  • Don’t ignore signs of water leakages
  • Do replace the RO membrane after at least 3-4 months
  • Don’t use bleach to rinse any tubes but the fifth polishing tube.
  • Do use bleach solely on the T-junction and not any other part of the 5th tube
  • Don’t disconnect the polishing membrane canister in a 4-stage RO filter system from the central unit
  • Do replace the O-ring for the first three canisters every time you replace the filters
  • Don’t take out or put in any membrane–for a 4-stage, 5-stage, and 6-stage RO filter system– with your hands. Always use a plier.

How Often to Replace Reverse Osmosis Filters?

Now that you know how to change reverse osmosis filters let’s talk about how often to replace reverse osmosis filters. RO filters should be changed every 12 months, even if you feel they aren’t that dirty.

Reverse Osmosis filters last longer than traditional filters, which is why you won’t have to worry about checking on them every few weeks. However, you shouldn’t miss signs of dirty filters either.

Dirty filters won’t get the job done correctly, so if you see muddy, discolored, or dark water which tastes funky, that’s your cue to change the RO filters.

How often to change reverse osmosis filters also depends on what type of filter you are changing.

How Long Does A Reverse Osmosis Water Filter Last?

A reverse osmosis filter lasts at least two to three years, depending on usage. Sometimes, it so happens that only some parts of a reverse osmosis filter get dirty or damaged, which is why you shouldn’t only know how to change reverse osmosis filters and how to change only one specific component of the filters.

How Often to Change A Sediment Filter?

In all RO filters, the first filter is a sediment filter which removes dirt and large particles of debris. A sediment filter lasts 6 to 12 months; around the same time, you should replace it.

How Often to Change An Activated Carbon Filter?

Activated carbon filters last 18 to 24 months, depending on how much they are used. If your RO filter uses its carbon block filter and runs 24 hours a day, you may need to replace it earlier than 18 months.

How Often to Change Deionization Filter

There is no set timeline to when you should change a deionization filter, but if you have a large water capacity, you may need to check in on the filter after 3-4 months.

How Often to Change Mineralization Filter

A mineralization filter lasts nearly a year or more, so you should change it every 12 months.

How Do You Change Reverse Osmosis Membranes?

To change a reverse osmosis membrane, you must disconnect it from every connection. Then unscrew the membrane cap and remove the membrane. Insert the new membrane and close the canister. Reconnect the hoses.

  • Turn off the main water line. If your RO directly connects to a refrigerator or faucet, disconnect that source.
  • Open the RO faucet so any water stored in there will drain out.
  • Unscrew the main canister using a filter wrench.
  • Use pliers to slide the membrane out.
  • Inside the canister will be a lining rubber ring (the O-ring). Carefully slide it out.
  • You can clean the central canister, but to do that, ensure all connecting tubes are disconnected.
  • Attach the new O-ring and pop in the new membrane using pliers.
  • Close off the membrane cap using the filter wrench. Reconnect the hoses.

How Often to Change Reverse Osmosis Filters’ Membranes

You don’t have to clean RO membranes as frequently as the other filters, so that a general timeline would be every two years.

Of course, if you feel your water tastes funky or has a new or strange odor, you can change the RO membrane along with the periodic cleansing of the filters.

Common Mistakes With Changing RO Membranes

Even when you know how to change reverse osmosis filters, you can still face these problems during the process of changing:

Not Closing Off the Water Source

If you forget to close off the water source or don’t do it properly, your RO system won’t work efficiently even after you install a new membrane. Not closing the water will make changing any filter or membrane very messy.

Not Knowing Which Pipe Goes Where

The hoses/pipes on a membrane are not marked, so that a beginner can confuse them. Attaching the wrong hose can lead to severe problems, including contamination of the water source and damage to the RO system.

Not Pressing the Tabs on the Lid

If you don’t press the tabs on the lid while pulling the hose, you won’t be able to pull the hose out. Even if you manage to get the hose out, you might have damaged the hose or the canister.

Using Hands to Pull the Membrane Out

You don’t have to change RO membranes for at least a year or two, which is why they’ll be really jammed up in the canister. If you’re using your hands to pull out the membrane, you’re only wasting your time and energy. Instead, use a plier to pull out the membrane slowly.

Improperly Attaching the O-Ring

The O-ring doesn’t magically slide onto the groove; you have to fit the O-ring and ensure it’s properly sealed. Improper attachment of the O-ring can result in membrane detachment even after you close the canister.

How Long Do RO Membranes Last?

RO membranes easily last two years or more, but this duration can change depending on their type and how much they are used.

Types of RO Membranes

There are two main types of RO membranes, a Cellulose Acetate (CA) membrane, and a Thin Film Composite (TFC) membrane.

To know how to change reverse osmosis filters and their membranes, you should know what kind of membrane you have. While the type of membrane does not affect the process of changing filters, it can help diagnose problems with the filter and membranes in general.

1.    Cellulose Acetate Membranes

The CA membrane can tackle chlorine in water like a boss. Removing chlorine is essential because it can react with the inner layering of the tubes and make the water dirtier than it was before filtration.

2.    Thin Film Composite Membrane

TFC membranes are like a giant sieve that purifies water. TFC strongly reacts to major salts and can improve water quality

Which is the Better Membrane?

A CA membrane is better at tackling chlorine and protecting the RO system, but a TFC membrane is better in the long run. You’ll find CA membranes in older RO systems, but newer ones use TFC membranes.

A CA membrane won’t need a replacement for 3-5 years of use. It would be best if you replaced a TFC membrane every 1-2 years.

How to Know if RO Membrane is Bad?

Of course, while you should know how to change reverse osmosis filters, knowing when a filter needs changing is also essential. Following periodic RO filter changes is recommended, but you can’t wait for the filter to wear out naturally.

Some signs tell you that your RO membrane or filter is going bad.

These include:

  • Sudden noises coming from the faucet
  • The water flow suddenly reduces
  • The taste of the water changes
  • The water’s color pales or becomes slightly grey
  • There is a funky or strange odor coming from the water
  • There are leaks in the RO system
How To Change Reverse Osmosis (RO) Filters?

Summary | How To Change Reverse Osmosis (RO) Filters?

Knowing how to change reverse osmosis filters is essential because you can’t always rely on a technician or plumber to do it. It is also necessary to recognize signs of a bad RO filter or membrane because it takes some users a long time to know something is wrong.

RO filters last a year or two but can wither or wear down due to excessive use. But this isn’t a problem you can’t fix; learn how to change reverse osmosis filters, and you’ll be good to go.

You can change 3-stage, 4-stage, 5-stage, and 6-stage RO filters at home, as long as you do it correctly. There are many mistakes that a beginner makes while changing RO filters, but if you follow this detailed guideline, you won’t have to worry much.


This is my blog about the ways and solutions that can help you improve your health by taking more value from drinking water. As improving health means a lot to me, I decided to create the Water On Top project with the purpose to reveal the benefits of water, the finest products to take our daily water to another level, and much more great stuff about water that I believe is on top of our nutrition.

Recent Posts