How Often Should I Change My Water Filter?

One critical step after purchasing your water filter.

By: Maggie Irish

You’ve done your homework, talked with a plumber, budgeted it all out, and now you’re taking the final step: purchasing a water filter. The rest is pretty easy. You put the filter in and it does the hard work: capturing contaminants before they cause your family harm.

However, there is a critical, ongoing step to ensure your water filter continues to do its job long after install: you must change your water filters.

Why filters need to be changed

Now you might wonder why filters need to be replaced. It’s simple, really. If you don’t replace your water filter, contaminants will clog the filter, leaving no room to capture any other chemicals or particles, which will then flow out along with the water.

"If you don’t replace the cartridge in your filter, contaminants will clog the filter, leaving no room to capture any other chemicals or particles, which will then flow out along with the water.”

This can also mean that your filter becomes a petri dish past its expiration date, acting as a bed for bacteria to grow and multiply. Imagine drinking that with your post-workout dinner.

As you rush to figure out when you bought your filter and when you should be replacing the cartridge, it is important to first know which system you have.

Determining which water filter you have

With a wide variety of filters on the market, it’s important to note that not all replacement schedules are the same. The change frequency of your water filter will depend on the system type, brand, and specific model. Most household drinking water filters last between 6 to 12 months and need to be changed to maintain effectiveness. However, some filters like those in pitchers have shorter lifespans and may need to be replaced every 1 to 2 months. On the other hand, some whole house water filters can last between 5 to 10 years. This can also be confusing if your system uses multiple stages of filtration, with each stage having a different replacement schedule.

To determine how long your filter lasts and how often it needs to be replaced, start by finding the exact system you have. Keep a copy of the manual, and if you lose it, try checking your product for a serial number or label indicating the model so you can look up the replacement schedule online.

How often water filters need to be changed

Whole house

First, there are several different types of filters involved in a whole house system including the pre-filter, main filter, and post-filter, plus you may have some optional add-ons that also need maintenance. The lifespan of a whole house system’s main filter can vary widely, lasting anywhere from 1 to 10 years. We’ll cover whole house replacement schedules for our systems and add-ons, which should give a reference point for the type:

Let’s start with the pre-filter:

  1. 20" Pre-Filter: This is the standard pre-filter included with all of our Rhino® whole house systems. Replace it every 2 months.
  2. Low Maintenance Pre-Filter: This is our enhanced pre-filter for our whole house systems that lasts three times longer than our 20" Pre-Filter. Replace it every 6 months.
  3. OptimH2O® Pre-Filter: Designed specifically for the OptimH2O® Whole House System, this pre-filter should be replaced every 6 months.

Then, take a look at your main filter, as it has its own replacement schedule as well:

  1. Rhino® and Rhino® Max Flow tanks: The main filter should be replaced every 10 years or 1,000,000 gallons.
  2. Rhino® Chloramines and Rhino® Chloramines Max Flow tanks: The main filter should be replaced every 10 years or 1,000,000 gallons.
  3. Rhino® Well Water with UV: The main filter should be replaced every 5 years or 500,000 gallons.
  4. OptimH2O® Filter Replacement: The main filter should be replaced every 12 months or 100,000 -- Whichever comes first.

When it comes to your post-filter, Aquasana uses the same 10" Post-Filter across all of our whole house systems and these should be replaced every 6 months.

Lastly, if you have any add-ons to your whole house system, don’t forget those need maintenance too. The Aquasana UV lamp is a popular addition for many whole house users that helps protect homeowners from bacteria and water-boil warnings. UV lamps need to be replaced every 12 months, but make sure to confirm if you need the original lamp or a new lamp replacement.

If you’re using our Salt-Free Water Conditioner, we recommend you replace your tank every 10 years or 1,000,000 gallons. Conditioners used with the Rhino®, Rhino® 600,000 Gallons, and the OptimH2O® need to be replaced with the base Salt-Free Water Conditioner replacement. If you have a conditioner for the Rhino® Max Flow, Rhino® Chloramines, Rhino® Chloramines Max Flow, and Rhino® Well Water with UV — replace it with the tall Salt-Free Water Conditioner replacement.

Under sink water filters

Because under sink water filters are much smaller than whole house systems, they need to be replaced more frequently. In general, you can expect an under sink to require replacement every 4-6 months, though RO filters can last longer. Here’s how often our under sink filters need to be changed:

  1. Claryum® 2-Stage: Replace every 6 months or 500 gallons.
  2. Claryum® 3-Stage: Replace every 6 months or 600 gallons.
  3. Claryum® 3-Stage Max Flow: Replace every 6 months or 800 gallons.
  4. Claryum® Direct Connect: Replace every 6 months or every 784 gallons.
  5. SmartFlow® Reverse Osmosis:


Claryum® Direct Connect

Easy to install, fast-flowing filter connects directly to your existing faucet to reduce 78 contaminants.

Countertop water filters

Countertop systems frequently utilize a single filter, so you won’t have to keep track of replacement schedules for different stages. However, countertop water filter lifespans are typically the shortest, with some systems and pitchers requiring replacements every 1 to 2 months. We offer one countertop filter, the Clean Water Machine. The filter will need to be replaced every 6 months and can be swapped out in a matter of minutes.

Shower filters

Shower filters help remove chlorine that’s harsh on your hair and skin, and similar to countertop filters, they frequently utilize a single stage of filtration which makes replacements easy. In general, you should replace your shower filter every 6 months to maintain its effectiveness.

Our shower filters utilize SimplySoft™ coconut shell carbon and Copper-Zinc (KDF) media filtration that reduces 90% of chlorine for a cleaner, healthier shower experience and the replacement cartridge should be swapped every 6 months.

Get replacement filters auto-shipped when you need them

A dirty filter can become a source of bacteria and mold, and can eventually cause your system to stop working altogether. However, keeping track of how long your filters last and replacement schedules can be overwhelming. That’s why we started Water for Life® — our filtration subscription service.

Water for Life® will keep track of when it’s time to change your Aquasana water filters and will ship a new set of filters to your door when you need it. The benefits of Water for Life® include:

  • Extended limited warranty – free replacement parts when needed
  • 15% off the price of replacement filters
  • Free shipping
  • No contract required

To get started with Water for Life®, simply click the “Water For Life Price” when adding a product to your cart, or reach out to one of our Water Experts at 866-662-6885 or