Review: Culligan FM-15A & FM-25 Faucet Water Filters

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Why review the Culligan FM-15A and FM-25 faucet mounted water filters together? Because the only difference between them is their color.

The Culligan FM-15A has a white finish (looks a little cheap to be honest), whereas the FM-25 comes in a “chrome” design (plastic with chrome coating).

Personally, we prefer the latter because it blends better with other kitchen fixtures and costs only slightly more.

Be that as it may, both units provide a simple solution for better tasting and somewhat cleaner drinking water free from odors…

Culligan FM-15A

Culligan FM-15A

Flow Rate:0.5 gpm
Filter Capacity:200 gal
NSF Certifications:42, 53
Warranty:2 Years

Our Rating

Culligan FM-25

Culligan FM-25

Flow Rate:0.5 gpm
Filter Capacity:200 gal
NSF Certifications:42, 53
Warranty:2 Years

Our Rating

Culligan FM-15A and FM-25 Faucet Filters – Key Features

The carbon block filter that is used was tested and certified against NSF Standard 42 and Standard 53 for the reduction of:

  • Sediment
  • Turbidity: 99.1%
  • Bad taste & odor
  • Chlorine: 97.4%
  • Lead: ≥98%
  • Lindane: 98.9%
  • Atrazine: 94.7%
  • Particulate class I: 98.3%

As you can tell, what we are looking at are faucet mounted units that fulfill basic filtration needs.

Service flow rate: 0.5 gpm at 60 psi. Minimum/maximum pressure limits: 30-100 psi.

FM-15A & FM-25 Pros

What we like? First of all, both faucet filters install within minutes. Plus adapters for almost all standard faucets are included.

Furthermore, a simple diverter tab allows you to quickly switch between filtered and unfiltered water. This will greatly extend filter lifetime as you can use regular tap water for purposes other than cooking and drinking which in turns lowers maintenance cost.

Last but not least, you get a 2-year limited warranty against all defects in materials and workmanship when used complying with the use and care manual.

Culligan FM-15A

The Culligan FM-15A – learn more on

Culligan FM-25

The Culligan FM-25 – learn more on


Like we said, the Culligan FM-15A/FM-25 attach in under 3 minutes, no tools required.

In case your faucet has internal threading you have to use 1 of the 2 included adapters.

Please note: Adapters may not fit all (standard) faucets. You can verify the thread size with your faucet manufacturer to ensure compatibility.

Want a more detailed rundown of how to do the setup?

  1. Remove the aerator from your faucet. Make sure to save the gasket for later use.
  2. For internal threading, select the appropriate adapter + washer. Screw them on. Hand-tighten only.
  3. Attach unit to the faucet. Turn swivel collar to tighten onto threads of faucet. Avoid using pliers to not break the plastic.
  4. Turn on the water. Pull out the diverter tap.
  5. Check for leaks and let the cartridge flush for 10 minutes to remove any residual carbon fines.


Since many of you prefer video, here is one that explains how to quickly install the Culligan FM-15A & FM-25 step by step:

The Package (Parts)

  • Faucet mount unit
  • 2x faucet adapters
  • Carbon block cartridge


Each filter cartridge needs replacement every 200 gallons or 2 months, although cartridge life can vary depending on your water usage and conditions.

Annual costs are considerably higher than what you pay for most other faucet mounted units.

How to replace the filter? Don’t worry, it’s not difficult at all – at least in theory (more on this in a bit):

  1. Simply unscrew the cap from underneath the housing. The cartridge will drop down into your hand.
  2. Dispose of the old cartridge
  3. Insert a new one. Turn 2 and a half full turns until it stops.
  4. Open the faucet and check for leaks. Tighten cap if need be.
  5. Flush the new cartridge for at least 10 minutes to remove all carbon fines.


For all the details we recommend you refer to the manual.

FM-15A & FM-25 Cons

The biggest issue that users have with the Culligan FM-15A and FM-25 is that they can’t get the filter housing open. After a couple of days/weeks use the cap gets stuck and simply doesn’t move which makes the whole replacements process a pain.

Even holding the bottom part with pliers and twisting with the other hand to get more leverage does not work for everyone.

Another drawback is that pull-down and pull-out faucets are incompatible, as well as a number of standard models. This is why we consider it a good idea to double-check with the manufacturer whether or not these filters will fit your faucet before you spend any money.

What’s more, we read reports about leaks along seams or due to cracked filter compartments and customers receiving defective products.

Culligan FM-15A & FM-25 Review: Our Verdict + Best for

One thing is for certain, the water you get from a Culligan faucet mounted filter tastes better than plain tap water. This, of course, is what’s most important. And although flow is a bit slow, the Culligan FM-15A and FM-25 are easy to use, they blend in nicely with other fixtures, and they are some of the best for filtering out lead and chlorine.

That being said, for our final verdict we also have to consider apparent design flaws and the costly replacement filter elements.

In the end, we award 3.5 stars each!

More Reviews:

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This completes our Culligan FM-15A and FM-25 review. If you have any questions please don’t hesitate to leave a comment below!

About the Author Gene Fitzgerald

Gene Fitzgerald has been with BOS since the very beginning. She is head of content creation and has fully immersed herself into the home water treatment industry only to become an expert herself. Outside of BOS, Gene loves reading books on philosophy & social issues, making music, and hiking.
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Leave a Comment:

Chakolate says September 4, 2019

Before installing a new filter, I swipe the threads with olive oil. After a few months, it works stiffly, but much better than without the oil. I can do it with my 67-yo female hands. 🙂

    Gene says September 5, 2019

    Thanks for sharing, Chakolate!

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