Reverse Osmosis Filter Replacement And RO Membrane Guide

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Reverse Osmosis Filter Replacement And RO Membrane Guide

Reverse osmosis (RO) filtration removes harmful impurities, pollutants, and contaminants from your tap water – but that means the filters get worn out! Following a regular reverse osmosis water filter replacement schedule is essential to maintaining the performance of the system over time.

But with so many different types of reverse osmosis systems on the market today, knowing how to replace them can be a challenge.

In this guide, I will walk you through what type of replacement filter or membrane you need for your reverse osmosis system and tips on how to change it correctly. I’ll also provide helpful advice on when should you replace each component in your RO system.

Key Takeaways:

  • Reverse osmosis filters need replacement every 3 – 6 months
  • Reverse osmosis membranes need replacement every 12 – 24 months
  • Replacing the filters is an easy process that takes less than 15 minutes
  • The average cost for a filter replacement set is between $65 – $135
How Does Reverse Osmosis Work_Reverse Osmosis Stages Diagram

All home water treatment solutions require maintenance, and reverse osmosis systems are no exception. The timing of when to replace the various components in an RO system will depend on the model you have and how frequently it is used.

Here’s a recommended schedule for how often reverse osmosis filters and membrane should be changed:

  • Sediment Pre-Filter: Replace the sediment filter every 2 – 6 months.
  • Carbon Pre-Filter: Replace the pre carbon filter every 6 – 12 months.
  • Reverse Osmosis Membrane: Replace the reverse osmosis membrane every 12 – 24.
  • Carbon Post Filter: Replace the post carbon filter every 6 – 12 months.
  • Remineralization Filter: Replace every 12 months.

These recommendations are based on general usage, so if you have a high-usage RO system then you may need to replace the filters more frequently.

How To Change Reverse Osmosis Filters And Membrane

Now that you know when to replace your reverse osmosis filters and membrane, the next step is to learn how to install them. Fortunately, it is a much easier task than when you initially installed your RO system!

How To Change Reverse Osmosis Filters

Let’s start with how to change reverse osmosis filters. Installing a new reverse osmosis filter is fairly simple; you will need to locate and remove the old filter first, then insert the new filter into the filter housing. Make sure that you follow these steps carefully:

What is reverse osmosis and how does it work

Reverse Osmosis Water Filter Replacement Steps:

Estimated Time: 15 Minutes

1. Get The Correct Replacement Filter

While most cartridge filters are universal and can fit in any RO system, it’s still important to double-check that you have the correct replacement filter for your particular model. If your system has an integrated filter, you will need to replace it with the specific manufacturer filters (this goes for tankless models too)

2. Shut Off The Water Supply

Before attempting to replace the filter, make sure the water supply is shut off to avoid any potential leaks or damage. And make sure to remove any pressure from the reverse osmosis system by opening an air gap faucet or storage tank valve.

3. Remove The Old Filter

Using a spanner wrench or pliers, carefully unscrew the old filter housing from the filter manifold. Make sure not to force it as this can cause damage to your reverse osmosis system. Many times you will be able to loosen it with your hands. Note that if you have a cartridge-style filter, there will be water still inside the housing.

4. Clean The Filter Housings

Once the old filter is removed, clean the empty filter housing cylinders with a soft cloth to remove any dirt or debris. Filter housings need to be sanitized so that mold and bacteria do not grow over time. Also, examine any o-rings on the top of the housings to make sure they are not damaged or cracked. If they are, you will need to replace them. Make sure the o-rings are lubricated.

5. Install The New Filter

Insert the new reverse osmosis filter into its filter housing making sure it is seated properly. Start by hand screwing it back onto the manifold so it is not cross-threaded, and secure it tightly using a wrench or pliers. Make sure not to over-tighten as this may cause damage.

6. Turn The Water Back On

Once the new filter has been installed, slowly turn the water back on and run your air gap faucets for a few minutes to make sure the filter is working properly. You should hear the storage tank begin to fill. Inspect the system for any leaks at this time.

7. Flush The System

Allow the RO water dispenser to run for several minutes to prime and flush the new filters. Seeing small particles of carbon is normal as you flush the system. Once the system is flushed, you are safe to use your reverse osmosis system!

Estimated Cost: 70 USD


  • Replacement filters
  • Spanner Wrench
  • Orings
  • Lubricant

How To Replace RO Membrane

Now let’s cover how to install an RO membrane. Replacing an RO membrane isn’t quite as straightforward as replacing a filter, and requires a few more steps.

1. Shut Off The Water Supply

Like with the filters, you’ll need to shut off the water supply before attempting to replace the reverse osmosis membrane. Make sure to remove any pressure from the system by opening a faucet or ball valve.

2. Unscrew The Filter Housing Cap

Using a wrench or pliers, carefully unscrew the cap from the RO membrane housing. If you have a tankless reverse osmosis system, you generally twist out the filters with your hand.

3. Remove And Discard The Old Membrane

Once the cap is removed, remove and discard the old RO membrane. Make sure to dispose of it properly; do not reuse it under any circumstances as this could lead to health hazards.

4. Clean The Membrane Housing

Using a soft cloth, clean the empty membrane housing to remove any dirt or debris that may have built up over time.

5. Insert And Secure New RO Membrane

Insert the new membrane into the RO membrane housing and secure it tightly using the cap. Make sure not to over-tighten as this may cause damage.

6. Turn The Water Back On

Once the new membrane has been installed, turn the water back on and run your faucet for a few minutes to make sure everything is working properly across the entire reverse osmosis system. The storage tank will now begin to fill.

And there you have it; replacing your reverse osmosis filters and membranes is really quite simple!

What Happens If You Don’t Change Reverse Osmosis Filters?

If you don’t replace your reverse osmosis filters and membrane regularly, it can lead to a variety of problems, including:

  • A decrease in water flow due to clogged or dirty filters
  • RO membrane performance will suffer and allow harmful contaminants to pass through
  • The reverse osmosis system will fail over time, leading to costly repairs or replacement
  • Mold will begin to grow in the storage tank and filter housings

Not replacing the filters and membranes on reverse osmosis systems on a regular basis will harbor bacteria and other impurities. If these contaminants make their way into your drinking water, it can lead to serious health problems. So be sure to keep up with your RO system maintenance – it will keep you healthy and save you money in the long run!

How Much Does It Cost To Change Reverse Osmosis Filters

The cost to change the filters on a reverse osmosis system depends on how many stages the unit has. A typical point-of-use RO system with 3 stages will cost on average $90 per year to replace the filters and membrane. If the system has additional filters, like a remineralization filter, the annual cost to change filters will be higher. Here is a breakdown of the cost of common reverse osmosis system filters:

  • Sediment Pre-Filter: Cost on average $20 – $30
  • Activated Carbon Filters: Cost on average $30 – $40
  • Reverse Osmosis Membrane: Cost on average $60 – $110
  • Remineralization Filters: Cost on average $25 – $30

The price for replacement filters will depend on the brand and overall quality. Although it isn’t mandatory, searching for NSF-certified filters is a positive, but will likely cost slightly more.

How Long To Run Reverse Osmosis After A Filter Change?

Though you may be tempted to turn your system back on right away after a reverse osmosis filter or membrane change, it’s recommended that you allow the system to run for at least 20 minutes before using the water. This will give the filters and membrane time to purge out any air bubbles that may have formed during the exchange process. And if you’re replacing both the filters and membrane, it’s recommended that you run the system for at least 40 minutes.

It’s also important to note that you should replace all of your RO filters and membranes every 6-12 months to ensure optimal performance. With proper maintenance and care, a reverse osmosis system can last for years!

How To Tell If RO Membrane Is Bad?

If you’re wondering if your reverse osmosis membrane is bad, here are key signs to look for:

  • A decrease in water flow and production from the storage tank
  • Increase in TDS (total dissolved solids) readings or water contamination testing results
  • An unusual taste or smell in your drinking water

If you notice any of these issues, it’s time to replace the membrane.

Furthermore, if you’ve had your RO system for a while, you may want to proactively replace the membrane every 12 – 24 months. Over time, sediment can build up in the filters and prevent them from functioning optimally. Additionally, high water pressure and extreme temperatures can also damage the membrane over time. Replacing the membrane regularly will ensure that you’re getting the best performance out of your RO system.

Final Thoughts

Replacing reverse osmosis filters and membranes is an important part of maintaining your RO system. It’s simple to do, and doing so regularly will help extend the life of your reverse osmosis system and ensure you have clean safe drinking water. So don’t forget – change those filters!

Happy hydration!

Frequently Asked Questions

Is reverse osmosis water filter replacement difficult?

No, replacing the reverse osmosis water filters is an easy task that takes less than 15 minutes. It generally requires no tools, but if the filter housing is stuck, you may need a wrench to loosen it.

How much do reverse osmosis replacement filters cost?

Generally, the pre and post-carbon replacement filters cost approximately $30, while the RO membrane may cost $50 to $100. If your system includes a remineralization filter, that will cost around $30.

How often do RO filters and membranes need to be changed?

Reverse osmosis filters will generally last 3 – 6 months before changing them. The reverse osmosis membrane will last between 12 – 24 months. The filter life depends on the quality of your water and your water usage.

What’s the difference between a reverse osmosis filter and membrane?

A reverse osmosis system uses several stages of filtration. The first stage is typically a carbon pre-filter. Next, water passes through the actual RO membrane which is a semipermeable filtration membrane. Lastly, water will go through a carbon post filter.

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