How Often Should I Change My Reverse Osmosis Filter?

How Often Should I Change My Reverse Osmosis Filter?

The importance of regularly changing the filters in your reverse osmosis system can't be stressed enough. And we get it, you might be thinking "ugh, replacing RO filters is such a pain!" 

And you're not wrong. It can be a bit of a hassle.

But it's definitely worth it to keep your water clean and healthy. Because most RO system owners aren't quite sure when to swap out their filters. And that can lead to big problems:

  1. Over time, your filters will start to collect contaminants from your water. And that can make your water unsafe to drink (not to mention taste bad).
  2. A clogged filter can also put a strain on your RO system and shorten its lifespan.

And depending on the quality of water going into your system and your total water usage, you may need to change the filters more often than the standard suggested schedule.

Don't worry- that's what this guide is for.

In this guide we'll share some tips and tricks for knowing when it's time to change your filter, and how to do it properly to make sure your system lasts as long as possible.

Trust us, it's worth the effort to keep your water quality top-notch for you and your family.

How can I tell if I need to replace my filters?

When your water starts to taste a little off, it might be time to replace your filters.

There are a few ways to tell if your filters need to be changed.

  • Check your replacement schedule. Most filters need to be replaced every 6 months. So if it's been 6 months or longer since you last changed your filters, it's probably time to swap them out.
  • Check the TDS of your water. TDS stands for Total Dissolved Solids, and it's a measure of the amount of impurities in your water. Ideally, you'll want your TDS to be between 50 and 150. If it's higher than that, consider replacing your filters.

Of course, there are times when you'll need to replace your filters more often. For example, if you live in an area that's been affected by a natural disaster or if there's been a contamination event, you'll need to change your filters sooner.

So it's important to have a plan other than the taste test to find out when you should replace your filters.

Flushing my system before replacing filters

Flushing the system

When you replace your filters, it's important to clean your system and run a sanitizer through the tubing and storage tank.

This will help prevent the buildup of bacteria, slime, and other nasty stuff.

Here's how to do it:

  1. Turn off the water input valve and completely drain your storage tank.
  2. Remove all the filters from their housings, including the RO membrane and polishing filter—even if they’re not being replaced—and screw in the housing covers without the filters installed.
  3. Before reattaching the first stage housing, pour about 1 cup of hydrogen peroxide into it.
  4. Turn the water input on and let the storage tank fill.
  5. Turn on your reverse osmosis faucet and let the tank drain and then fill once more.
  6. Switch your input valve to the ‘off’ position, drain your storage tank again, and then install and/or replace the filters.
  7. Run your system through one more rinse cycle, and then you’re ready to go!

    From there just make sure you find the right replacement filter(s) for your system.

    Note: If you don't know just contact us by chat, email or phone and we'll help you find the right ones.

    And now you're all set, let's talk about the best time to replace your filters.

    Nu Aqua 5 Micron Sediment Filter: Replace every 6-9 Months

    Your sediment filter is your first line of defense against all the nasty stuff that can get in your water, like sand, silt, rust, dirt, and other debris. 

    When your sediment filter gets clogged, it can restrict the flow of water through your system and shorten the lifespan of the other filters. So it's important to change your sediment filter regularly.

    1. If you have well water that's heavy with sediment, you may need to change your filter every six months.
    2. If your water has low turbidity, you may only need to replace it once per year (every nine months).

    Nu Aqua's transparent sediment filter housing makes it easy to see when it's time to change your filter. Just look for sediment buildup in the chamber. Once you see sediment buildup, it's time to change your filter.

    Granular Activated Carbon (GAC) Pre-Filter and Coconut Carbon Block Filter: Replace every 6-12 months

    GAC filters are essential for protecting your RO membrane from chlorine and other harmful contaminants.

    Chlorine and other chemicals are used to disinfect municipal water supplies. And while it's effective at killing bacteria, it can also be harsh on your RO membrane. In fact, they can cause it to break down prematurely and lead to system failure.

    They're are made from activated carbon, which has a very porous surface that attracts and traps contaminants. When water passes through a GAC filter, the chlorine and other harmful chemicals are absorbed by the carbon, leaving behind clean, pure water.

    Nu Aqua offers not just one, but two carbon pre-filters in their 5-stage systems. The first filter removes the majority of the chlorine, and the second filter removes any remaining traces. This ensures that your water is completely free of chlorine before it reaches the RO membrane.

    Reverse Osmosis Membrane: Replace every 1-2 years

    The reverse osmosis membrane is the heart of the system. It's what removes all the bad stuff from your water, like heavy metals, minerals, pesticides, and salt.

    • Your membrane can last for more than a year, and even up to three years if you start with softened water.
    • If you have hard water, the membrane will wear out faster. That's because hard water has more minerals to process, putting wear on your system.

    If you notice that your water output is suddenly sluggish, or if you start to notice any strange flavors in your water, it's a sign that something is wrong with one of the filters.

    The best way to check for problems is to use a Total Dissolved Solids (TDS) meter.

    • The higher the TDS reading, the more impurities are in the water.
    • Again, make sure you're between 50-150 TDS.

    And don't worry, All Nu Aqua Platinum Series reverse osmosis packages come with a complimentary TDS meter included. This way, you can test the quality of your water on a regular basis and know immediately if your system needs maintenance.

    Carbon Polishing Filter: Every 1-2 years

    Nu Aqua’s T33 finishing carbon polish filter uses activated coconut shell carbon in granulated form to put a finishing touch on the water before it comes from the faucet.

    Since the only water going through it has already been purified, it doesn’t have much work to do compared to the others. 

    So when it's time to replace your filters, check out our convenient replacement filter sets, to help you keep your filter replacements on schedule.

    Because with proper care and reticular filter replacement, your reverse osmosis system will last for many years to come.


    Editor’s note: This post was originally published in October 2019. It has been updated for accuracy and comprehensiveness as of May 2023.