Clearly Filtered Under Sink Review

As a luxury under sink filter, this system excels in every regard. It’s pricey, but very easy to install and has top notch certifications.

Brian Adee, Senior Writer

David Lewis, Chief Editor

Last Updated:

Clearly Filtered Triple Stage Kitchen Faucet Filtration System

Though it’s pricey, the Clearly Filtered Under Sink Water Filter System exceeds expectations in every regard. It has best-in-class filtering certifications and is remarkably easy to install.

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What We Like
  • Huge filtering capacity
  • Easy to install
  • Excellent filtering certifications
What We Don’t Like
  • Large initial investment
  • Filter replacements are expensive
  • Big cost over time

If you’re shopping around for an under sink water filter, the Clearly Filtered 3 stage system will no doubt grab your attention. At double the price of many of its competitors, can it really be worth the investment?

That’s what our team is here to answer. By testing and examining dozens of under sink water filters, we’ve been able to synthesize a lot of information. And now, we’ll pass that on to you. By the time you’re finished reading, you’ll know exactly whether the price tag on Clearly Filtered’s under sink water filter system is worth the benefits it can bring to your home.


The most amazing part about Clearly Filtered’s under sink water filter system may be what’s not in the box. Open it up, and you’ll find:

  • Three filter cartridges
  • A mounting bracket
  • Two screws
  • Stainless steel braided lines
  • A manual

That’s it. No separate faucets. No difficult connections or fitting or tubing. Just the bare essentials necessary to hook the filter up to your existing cold water line. 

In fact, you don’t even have to mount it — it’ll work fine standing up on its own under your sink.

How It Works

This under sink water filter system uses three filtering stages. After attaching it to your existing water line, water flows easily through the large braided steel tubing.

Stage 1 is a premium carbon priming filter. It’s made from granulated coconut carbon. This mainly filters out aesthetic impurities like the taste and smell of chlorine. But it’s also capable of removing volatile organic compounds (VOCs) and common chemicals.

Stage 2 is a heavy metal and VOC filter. Its filter materials are proprietary and a highly guarded secret. It removes up to 99% of:

  • Heavy metals
  • Pesticides
  • Herbicides
  • Arsenic
  • Lead
  • Chromium
  • Radiation
  • PFAs
  • Emerging contaminants

Stage 3 is a fluoride and arsenic filter. It is also a proprietary design, and does not use reverse osmosis, bone char, or activated aluminum. Capable of removing up to 90.7% of fluoride from your water, and 99.9% of arsenic.


The proprietary filter designs for this under sink water filter put it in a class of its own. No other 3 stage filter system is capable of removing as many contaminants for as long as the Clearly Filtered.

It also meets three different NSF/ANSI standards:

  • Certification 42 means it’s guaranteed to remove aesthetic impurities. It makes water smell better, taste better, and run clearer.
  • Certification 53 qualifies it to remove known harmful contaminants such as lead and arsenic.
  • Certification 401 is more advanced. It covers “emerging contaminants” — things that may one day be regulated such as pharmaceuticals and microplastics.

That’s combined with an impressive 2000 gallon, 1 year filter life. In short: this under sink water filter is top quality in every performance aspect.

Flow Rate

The Clearly Filtered under sink water filter system has a streamlined design and installation. And it connects directly to your existing water supply. No need for a separate faucet. As a result, it maintains excellent water pressure and flow rate. In testing, we could barely tell a difference between our water pressure before and after installing this system.


No other under sink water filter system is as easy to install as the Clearly Filtered.

Even though it comes with a mounting bracket and screws, it doesn’t need to be hung to work. You can simply stand it upright against the back of your sink cabinet.

To illustrate just how easy it is to install, consider this: The record for installing it is 2 minutes and 2 seconds. And that’s using just a wrench and a screwdriver.

All you’ll need to do is turn off your water supply first. Then lay down a tool and unscrew your existing cold water supply. Connect the metal tubing from the Clearly Filtered in between the two sides of your cold water supply. And voila! It’s ready to go.

Filter Replacement

Filter replacements for the Clearly Filtered under sink system are so easy. Just twist off the old filters by hand. Then screw in the new ones.

Replacements should be made every 2000 gallons. For the average household, this will last 12 months or more. 

Unfortunately the filter replacements are almost as expensive as the system itself. You’ll definitely be paying a premium for the quality of their proprietary technology.

Build Quality

Build quality for every component of the Clearly Filtered system is exceptional. The stainless steel tubing is rarely seen in any other under sink water filter. The metal mounting bracket is well designed. And the filter cartridges are so easy to install and replace. So while the price is high for this system, the quality certainly matches it.

Warranty & Support

The Clearly Filtered 3 stage under sink water filter system is covered by a lifetime guarantee. Really. If you have problems with it at any point, the company will issue you a refund or replacement. And their US-based customer support is helpful and responsive via phone or email.


Clearly Filtered’s under sink system exceeds expectations in just about every regard. Its impressive certifications and huge filtering capacity are unmatched by almost any other under sink system. But you’ll pay quite a bit upfront for this top quality, and filter replacements aren’t cheap either.

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Frequently Asked Questions

What does the Clearly Filtered 3 stage under sink system cost per gallon?

Filter replacements cost $400 and filter 2000 gallons of water. This means each gallon of water from the Clearly Filtered system costs 20 cents.

How long does the Clearly Filtered 3 stage last?

Each Clearly Filtered filter cartridge lasts for 2000 gallons, or about 12 months.

What contaminants does the Clearly Filtered 3 stage remove?

This system removes up to 99.9% of 232+ contaminants. Some of the more notorious ones are: Fluoride, Glyphosate, PFAS (“non stick” chemicals), Lead, Chlorine