How Do You Know When to Change Reverse Osmosis System?

Filtering out harmful contaminants and substances from your water, a RO (Reverse Osmosis) system is one of the best ways to clean water. As such, it’s essential to ensure that you maintain the filters for optimal performance. Perhaps the most significant challenge we come across is being able to determine when to change the filter cartridge. Fortunately, this guide provides useful insight you can use to change the filters on time. How do you know when to change reverse osmosis filters?

Well, feel relieved because it’s a question that many have asked. Usually, the school of thought when it comes to filters is to have them changed after six months. While it’s an excellent starting point, you can still consider other time options. Various factors come into play when it comes to determining the longevity of your water filter.

For instance, factors such as the level of impurities, the amount of water, and the rate of use of the filter are all notable factors. 

Experts in this field recommend having the filter changed in relation to the amount of water it cleans. Usually, these are products with a specific life cycle, which is measured in the gallons of water it filters. That said, this guide only relates to the average amount of water use. It’s not always an accurate indicator because water use changes differently. More so, many factors come into play in terms of filter longevity. They include:

  • The condition of the water in terms of contaminants and the amount it can filter
  • If you have hard water, water with lots of minerals, this can lead to scale accumulation. This might clog up the filter
  • If you use more water than the conventional household
  • How well was your water cleaned and filtered? 

Ultimately, when a carbon filter gets clogged, or it fails to attract contaminants, it might become less ineffective to use. Thus, it may be the right time to have it replaced. For example, a standard 10-inch 1 micron and 5-micron carbon block cartridges, may require replacements after six months. Also, the cartridge has to have filtered over 4000 gallons of water. That said, remember that the amount of gallons indicated is based on the overall amount of water that has passed through the reverse osmosis system. Many, only think of the filtered water produced, which might be a mistake. 

Important Factors to Consider When Changing the Water Filter

important factors to consider when changing the water filter ​

A TFC membrane is the most crucial component of your reverse osmosis system. You will use it to remove 90% of the impurities that travel through the water. With adequate care, a TFC membrane should last for over one year. That said, they are delicate, and are prone to damage. If any hot water accidentally passes through the membrane. This might cause the system to freeze or even cause the membrane to dry out. These are the leading causes of TFC membrane failure. The membrane might also clog, or fail to perform if you don’t change sediment filters. You have to change these filters often enough because this helps remove particulate matter and chlorine from the water.

It’s easy to perform a test on your membrane. First, you have to measure the TDS of the tap and product water produced through the membrane, before it travels through the DI filter. Also, you can use a Triple Inline TDS meter, which can install on one of the probes between the DI cartridge and the membrane. 

Otherwise, you can just disconnect the water line from the cartridge, and collect some of the RO water produced from the membrane. Once it passes through the membrane, the water should be clean with well over 90% of impurities being removed. For instance, if your tap water TDS level averages 100ppm, then the TDS reading after the membrane should average at less than 5ppm.

Once the membrane lets more than 10% of impurities pass, then it’s time to install a new one. 

Signs That A Water Filter Needs Replacement

If you detect an odour in the water, or if the water has an unpleasant taste, then it might be time to have it replaced. More so, there could also be a significant decrease in water pressure, which is an excellent sign to have the filter replaced. Also, you can use visual indications, usually, in the form of LEDs, that will inform you of when to have the filters replaced. Remember to check the guidelines of the manufacturer, and ensure you never exceed their use limits.

Why Filter Changes Are Crucial

Why Filter Changes Are Crucial​

Replacing your filter as required ensures that your system functions effectively. Furthermore, you should always keep a backup filter on hand, to make it easy to perform change-outs. Plus, filters are sold in relation to specific brands, and you can easily find a part or model number through the company website. 

If you want your filter to remove contaminants continuously, you have to ensure its replaced at the correct time. Otherwise, the flow rate of the water produced from the system might decrease, and compromise the functionality of the filter. 

Remember to Check Reverse Osmosis Filter Buying Guides

Ensure your drinking water is safe and tastes good will have many benefits for your overall health. There are several faucets, sinks, carafes and countertops, which you can consider for your needs. The costs of filters change dramatically and can be available at different price ranges. Ultimately, the price determines quality, just like products you will find at a store. The list of popular brands to consider includes Whirlpool, GE, Asquasana and more.

More so, getting buying guides from top-rated consumer reports should provide useful information on using water filters. Consider factors such as the installation, convenience, and perform tests before buying a new filter. The ideal reports go in-depth into the quality, levels of contaminants in water, and EPA drinking water standards. Furthermore, a local or state health department may provide additional free kits, you can use to understand the water quality. 

Tips to Consider

If your tap water is reasonably clean and you don’t use lots of water, then you might be changing the filter cartridges prematurely. Alternatively, if the quality of your tap water is bad, or produce a significant amount of DI water, you may negligently be letting contaminants in your water.

Fortunately, there are many ways through which you can determine when to change the reverse osmosis filters. For instance, using a TDS meter, which measures the dissolved solids in parts per million (PPM) is ideal. Furthermore, HM Digital Inline TDS meters are also popular, because they let you take readings even as the system operates.

Ensure that you turn off the waterline before you replace the cartridge. Spilling a small amount of water is inevitable because there is no way to drain the water from an ROI system. Also, remember to keep a towel and a small bucket close by. 

Then remove the filter container by using a wrench or pliers, and then remove the cartridges or the membrane. When reinstalling canister, remember to use your hands only for tightening. Why? Because it’s a delicate component, and any damage might lead to leaks Whenever you change your RO filter cartridges, remember to produce a few gallons first, before you start preparing water for your tank. 

This process will help flush out carbon dust in the filter, and preservatives that are in the TFC membranes. Usually, these preservatives help to keep the membrane wet after sealing.

Common Water Filter Issues

1. Is the Dispenser Slow?

This is among the leading factors associated with poor filter performance. Is the water dispenser running slowly? Do you live in an area that has lots of “hard water”? If so, all of those minerals that are filtered from the water and ice can compromise your system. How? It can cause clogs, which in turn decreases the flow of water. 

2. Gross Ice

Also, one of the most critical aspects of replacing a water filter. If your filter has outlived its time, you may come across various issues with the ice your fridge produces. The ice might become cloudy or even taste bad. Changing the filter could help alleviate this issue, and help to restore the quality of your water. Such an issue on ice could also be associated with poor water tastes.

3. Can’t Remember the Last Time you Changed It?

Time passes, and we forget about little things such as water filters. It’s okay, there is no need to be difficult on yourself. It’s a common complication. The recommended lifespan for most fridge filters averages at six months. You can perform a quick check online for your specific filter brands and make.

4. Strange Tasting Water

When the water filters become clogged, they also lose their ability to absorb contaminants. You may notice that your tap water has an unusual taste. While sudden changes in the taste of water can occur due to other issues, likely, your cartridges are no longer fully functional. Change the cartridges, and test the water if the problem persists. 

5. Strange Smelling Water

Another sign that you need to change the cartridges is when you notice the water has a bad taste. Remember that this can occur due to various complications. That said, if the smell goes away once you replace the cartridges, it probably happened due to the water that accumulated in the filter.

Even if these signs don’t always appear immediately, they are good indicators that may have experienced a missed “service cycle.” That said, depending on the quality of your tap water, these signs might come up even before the scheduled replacement date. Thus, this may mean your tap water has a large amount of impurities, and you need to replace the cartridge more often. 

If you have trouble remembering the replacement dates, you can sign up for a reminder program. Some brands provide notifications in the form of emails or text messages to their clients.

How Do I Clean My Water Filter?

Remove the old filter from the pitcher. Usually, this process is simple if the reservoir is dry. Thus, never run water through the system before you change the filter. You may have to twist it slightly to help loosen the filter from the reservoir. 

If it’s applicable, you can consider recycling the older filter. Most water filtration systems have specific recycling partnerships. A good example would be Brita, which partners with TerraCycle to create a free recycling program for pitchers, bottles, filter systems and more.

  1. Also, wash your hands before you handle the new filter.
  2. Remove the new filter from the package. Then soak it in a bowl of cold water for a few minutes. Not all filters require a pre-soak, so check the user manual.
  3. Flush out the filter by running cold water through it for a few seconds.
  4. While soaking and flushing the filter, consider cleaning the pitcher by using some soapy or warm water. Also, dry it thoroughly to avoid the development of bacteria. Also, remember to use a non-abrasive cleanser that won’t damage the filter components. You can use a teaspoon of vinegar in some water, as a natural solution for killing bacteria. 
  5. Insert the flushed filter into the reservoir, and ensure that you line up the grooves. Then press firmly to ensure the seal is tight. Most filters will produce a click sound when you install them correctly.
  6. Even if you can clean your filter, consider changing it for the best results. Why? Because a new filter has activated carbon, which helps to pull out contaminants. Remember that most pitchers and filters are not safe for dishwasher use.

Do you want another convenient approach for cleaning filters that is affordable?

Consider teabags!

You can get activated carbon online or from a local pharmacy. Use a spoon to fill a clean and empty tea bag with some charcoal. Then, tighten the bags, to help reduce any chances that the charcoal will fall out.

Consider using two tea bags if you have a regular-sized dispenser. These operate in the same way as the filters above, so you might have to presoak them, and flush before consuming the water. Also, consider replacing these at the rate of 40 gallons even eight weeks. 

While it’s an affordable and eco-friendly technique, it typically does not work as effectively as the filters you may purchase from the store. 


You should know that various factors come into play in the quality of water you consume at home. How do you know when to change reverse osmosis filters? Just as mentioned before, factors such as the amount of water, water quality and filter brand are all crucial. While there is no specific amount for these filters, approximate metrics are available which you can use to keep track of the water usage.

Staying informed on your filter performances and functions is crucial for the quality of water you consume. Thus, use this guide to help you ensure you never come across poor quality water or ice from your fridge. 

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