How Often Should You Change Your Water Filter?

This is the single most important question you could ask or find an answer to when talking about water filtration. If you do not change your filter in a timely manner then there is a high likelihood that you will not be getting the quality water that you hoped for.

Here are some age-old adages that you've probably heard that relate to your water filter:

Better safe than sorry
If you can taste a difference, than you're too late
If you can't remember when you changed the filter, then it's been too long


We often get the question,

"How do I know when it's time to change my filter?" 

It's a good question! But the answer isn't always so simple. 


Many variables can affect the lifespan of a filter. And no filter lasts forever. 

The main variable is the quality of your tap water you are passing through the filter. It makes sense that if your water contains more contaminants then the filter will be exhausted faster than if it were used with water containing fewer toxins and contaminants.

But don't worry, we test our filters to the most rigorous NSF Standards 42, 53, 244, 401 & 477. So you can rest assured that your filters don't just stop working one day and leave you with contaminated water! Our filters don't last forever, but we have tested them throughout the claimed filter life so you don't have to worry about the performance dropping off drastically. 


Will the filters slow down when they are done?

The simple answer to this is it's possible, but more than likely, no. The speed at which water passes through the filter is not the primary indicator of a spent filter. In some cases it could even speed up. Not all contaminants are large enough to collect and clog the filter. Instead, we have rated them for a number of gallons, which is based on our scientific laboratory test data which shows us when filter performance starts to drop off. So if you are waiting for your filter to slow down, that could be a mistake!

Determining how often I should change my water filter.

All of our filter systems are 3rd-party tested by an EPA-accredited lab using the latest NSF standards for drinking water. The percentage removal shown in our test results is determined by how much a spiked solution of a specific toxin or contaminant is removed throughout the determined lifetime of the filter. It is safe to assume that the longer you use your filter, the less likely it is to remove the various contaminants. Think of the filter as millions of tiny, powerful magnets that attract the various contaminants found in your tap water. Once those magnets have all trapped the contaminants they were meant to, they can no longer trap anymore. That is why it is important to change your filter before this happens.

Note: Clearly Filtered's transparency with the filters test results and performance is critical to understanding and trusting our filtration technology. Many other filters either don't provide their testing data or do not abide by the same rules that Clearly Filtered does. For example, one competitor provides test results for their product, but if you read the footnotes of the testing you will see that the numbers are shown are only after 4 liters (just over 1 gallon) has passed through their filter!!! They then go on to claim that their filters last for 40 gallons, but provide no data to back up those claims.  We find this disingenuous. 

You can also read our blog here that explains the benefits of signing up for a filter subscription for your filter systems. Over half of our customers choose this options. Find out why. READ MORE > 

Here are some quick and easy steps determining how often you should change your water filter (depending on which filter system you use):


Find the filter you have below

How do I know when to change my Pitcher Filter?

Here are 2 tips to help you calculate how often to change your filter.

Remember, these are all based on our Independent Lab Test Results, personal experiences using our own products, and recommendations based on average water quality. Because water quality varies from place to place we always recommend changing your filter before your notice any specific change to your water passing through your filter.

As mama always said, "Better safe than sorry!"

We never recommend a pitcher filter is used longer than 6 months as once a filter has been exposed to water it can begin to oxidize and over time will no longer remove the contaminants at the level it once did.

Tip #1: How many people are using the pitcher and what are they using it for?

One of the easy ways of calculating how often you change your filter is just by the number of people using the filter. We try to remind you that although you might only have one or two people using the water that you should probably calculate in what else you use your water for as well (pets, plants, cooking, coffee, tea, etc.)

For a family (or high water consumption) we recommend changing your filter every 2-3 months

For a couple (or average water consumption) we recommend changing your filter every 3-4 months

For a single user (or low water consumption) we recommend changing your filter every 4-6 months


Tip #2: Do a simple math calculation to find out

Another way to determine the frequency that you should be changing your filters is to determine how often, on average, you fill your pitcher daily. Since our pitchers can filter 100 gallons of water, and the pitcher reservoir holds roughly 1/2 gallon, you should get about 200 fills of filtered water out of each pitcher. Here is the simple math equation to determine the amount of days between each filter change:

200 / # of Pitcher Fills per Day = Days Between Filter Changes

For example, I use my pitcher for 2 people, to cook, and to give to my dog every morning and night. I end up filling my pitcher about 2 times per day. So using the calculation above:

200 / 2 (times filled per day) = 100 Days

I should be changing my filter every 3 - 3.5 months or so. 

Our customer average for water filter change frequency for this product is every 4 months (Or one 3 pack of filters per year)

Now that you have calculated how often you should be changing your filter, can you say that you've been doing it correctly? Over half of our customers choose a filter subscription to help ensure they are getting their filters before their current filter runs out. Read why a filter subscription makes a lot of sense here.

Get a pitcher filter


How do I know when to change my 3-Stage Under the Sink Filters? 

This system should be one of the easiest to determine how often you change your filters (and it's one of the easiest filter changes as well!). Because the Under the Sink System only connects to, and filters, your cold water, it makes it a bit easier to determine the lifetime of the filters. 

Most people use their cold water for things like drinking water, washing produce, cooking, making ice, etc while washing dishes (where you use the bulk of your water) is usually reserved for your hot water. Because of this, based on research, flow rates of kitchen sinks faucets, and personal knowledge of the system we came up with a simple equation to determine the length you should go before changing the filters. 

For a family (or high water consumption) we recommend changing your filter every 9 months

For a couple (or average water consumption) we recommend changing your filter every 12 months

For a single user (or low water consumption) we recommend changing your filter every 15 months

This filter system can potentially slow down depending on what might be in your water to start, and how taxing that is one the filter, but it's much better to be safe than sorry here. All of our employees have the filter system installed in their homes and choose to either be on the 9-month change plan if they have families or the 12-month change plan if they are single or a couple. 

Our customer average for filter change frequency for this product is every 11.6 months.

Get a 3-stage replacement filter


How do I know when to change my shower head filters? 

These systems are the most likely of our filter systems in which our customers forget to change their filters on time. That means they are also the product we most recommend the filter subscription for as it is a great reminder. Even our CEO is signed up for a filter subscription for the shower heads in his home because he says he wants a reminder to change the filter!

How often should water filters be changed? The simplest way to know when the filters need to be changed is how often do you use the shower. 

If you use the shower multiple times a day (or high water usage) we recommend changing your filter every 2-3 months

If you use the shower once a day (or average water usage) we recommend changing your filter every 4-5 months

If you use your shower only a few times per week (or low water usage) we recommend changing your filter every 6 months

6 months is really the longest you should go without changing your filter. One unique thing about the shower head filters is that the casing is clear. You should be able to see a difference between a new filter and a used filter. In areas of high chlorine, you will see a green/blue tint to the used filter. 

Remember your filter is removing contaminants from the water that is beneficial for your skin and hair, but its also removing contaminants that can then be inhaled in the steam that a hot shower can create. It is imperative to change your filters on time.

Get a replacement shower head filter

How do I know when to change my bottle filter? 

The bottle filter is rated and tested to provide you with 25 gallons of clean, filtered water. Many times it is not easy to determine this exactly so we use the "how many a day do you fill your bottle" analogy to figure out how often you need to change your filter. 

Our bottles are 24oz but a little bit of that volume is displaced by the filter and straw. To make it easy we will assume that every 5 times you fill your bottle, which is one gallon of filtered water.

If you fill your bottle more than 2x per day you should change your filter every 3 months

If you fill your bottle 1-2 time per day you should change your filter every 4-5 months

If you fill your bottle 0-1 times per day you should change your filter every 6 months

When to change your bottle filter


READ NEXT: The Awesome Benefits Of A Filter Subscription


Posted on Mar 10, 2020 by Janice Blaha

I am getting up there in years, and never remember when to change my filter on my Whirlpool refrigerator until it lights up with a red h20 light, indicating that it’s time for a new one and by the time I see that and reorder, it gets here a week later than when I should have replaced it! Now,I’m signed up for every six months to make sure I have clean, filtered water to drink but it sure would make my life easier and happy to win a free lifetime supply!

Posted on Nov 04, 2019 by Kenneth Wilson

My family lives in: Switzerland (1 family and us), England (1 family) and United States (2 families).
Review of Water Pitcher/Filters
1. I bought the first filter design. New Pitcher design much better!
2. Easy replacement filter. I buy the 6 pack for savings – long lasting filter. Produces great tasting water.
3. Product is so good I bought a Clearly Filter Pitcher for each of my 4 daughters.

Posted on Jul 26, 2019 by KJ Park

Thank you for this info – it is very helpful in letting me know when to change filter. I do mark the outside of filter with date replaced & that helps to know approximately when to change. I am a single user.

Posted on Jul 26, 2019 by Mary Matteson

I am very happy with my pitcher and shower head filters. I also have the water bottle filters but it is difficult to get a stream of water through them even if I change the filter more frequently than necessary.
According to the instructions for frequency of changing my filters, 6 months is correct for my rate of consumption. I have a couple of filters on reserve because I used to forget to change the filters. Now I write on the box the date I should change it.

Posted on Jul 25, 2019 by Judy Boitt

I have a sheet on the counter and each time I fill up I mark the sheet..I have 2 big dogs and they drink a lot of water……so with my sheet of paper marking each time I use it keeps me aware of the usage. Works for me….

Posted on Feb 26, 2019 by Signe Jacobsen

I love my filters. I have drinking water and your shower heads.
Thank you for this information.

Posted on Jan 29, 2019 by Tev Brannan

Just signed up for the renewal service. Had it before but ordered too many at one time so had way more than I needed. I’ve purchased five pitchers-two for home, one for work, one in the RV and one for a gift. I’d say I’m hooked on Clearly Filtered pitchers! Thanks for a great product.

Posted on Jan 28, 2019 by TONI B

I have had Clearly Filtered pitcher for several years now, and the water always tastes wonderful. I have an extra filter for those just in case scenarios where a water pipe breaks or an algae bloom happens. Thanks for this info!!

Posted on Jan 28, 2019 by Cassie OConnell

Hi. The last time I ordered a filter I signed up for the automatic replacement. It’s only myself, so I’m hoping you’ll give me a heads up shortly before it ships out the next time. I don’t recall when I received the last filter, but I will make a note of it the next time. I like the water now very much. One odd thing I’ve noticed is with the filter, is the water bowls I give to my birds, small birds, doesn’t get slimy like before. Thanks, because that used to be the yucky part of cleaning up after them.

Posted on Jan 28, 2019 by Liz Severino

We drink a lot of water here, use it for cooking, our dog, and more, and, we have 3 pitchers in the refrigerator at all times. Whoever uses the pitcher, refills it when it gets low. So I am not going to know how many times a particular pitcher is being refilled. Any suggestions on how to determine what’s best regarding changing each of the individual pitcher’s filters? Is there any way you can design into the top of the pitcher, a “fill counter” to make it easier?

Posted on Jan 28, 2019 by Robert Ellis

I have always followed the directions when changing filters and I’m confident it is correct….really, it is simple. Bob

Posted on Jan 28, 2019 by Terry Mussina

I always have a few extra filters in a cabinet for the “just-in-case” scenario. You are the only filter I know of that is rated to remove radiation, pesticides, herbicides and bacteria! Basically a disaster preparedness filter if something bad happens (God forbid!)

Posted on Jan 28, 2019 by Mary Jones

I just ordered another filter to play it safe. I always mark it on my calendar when Ill need my next one. Great info

Posted on Jan 28, 2019 by Jeff F

I always thought I was changing my filters on time until reading this! This is extremely helpful and eye-opening to say the least. Just signed up for subscription for my pitcher and shower head to make it easier. Kepp up the good work Clearly Filtered!

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