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Under Sink Companion Filter for Whole House Structured Water Systems


(3 customer reviews)

Greenfield Water Solution’s Whole House Add-on Under Sink Companion 4 Stage Filter

Elevate your water purification with the Greenfield Water Solution’s Whole House Add-on Under Sink Companion Filter. This well engineered designed 4-stage filter complements the Quantum Hydro system, providing an extra layer of purification for a wide array of contaminants, including fluoride, nitrates, and other potential residual impurities.

Why an Undersink Filter is Crucial:

The Quantum Hydro system effectively purifies water for the whole house. However, certain contaminants, such as nitrates, are more efficiently and cost-effectively removed at the point of use. This is vital as nitrates are not absorbed through the skin and need to be eliminated from drinking water specifically. Beyond nitrates, this undersink filter also targets any residual contaminants that may remain after whole-house filtration, ensuring the highest purity and safety of your drinking water. This makes the undersink filter not just an addition but an essential component of a comprehensive water purification system.

Stages of Purification:

  1. pHA Technology (Stage 1): Utilizes pre carbon-based hydrogen catalyst technology for pH adjustment, boosting the capacity and effectiveness of the subsequent stages.
  2. TS3 Carbonblock (Stage 2): Advanced carbon filtration to remove a wide spectrum of contaminants.
  3. Mineralizer or Nitrate Filter (Stage 3): Critical for homes with nitrate levels over 0.5 ppm. Double nitrate filters ensure complete nitrate removal and address other residual contaminants.
  4. Coconut Carbon Polishing Filter or Second Nitrate Filter (Stage 4): The final stage that not only refines water quality but also improves taste.



  • Indicate your filter preferences in the checkout notes.
  • Note: This model is designed for filtration and does not structure/energize water. For a structuring model, [click here].


Installation and Dispenser Options:

  • Effortless installation, connecting to your cold water faucet.
  • Option to connect to a standalone stainless water dispenser.


Incorporating the Undersink Companion Filter with your whole house system ensures the utmost purity of your drinking water. It’s specially engineered to address nitrates and a spectrum of other potential residual contaminants, providing peace of mind and promoting overall health and well-being.

To customize for your particular water issues, email us with your zip code or well water report. 

Companion Filter Installation Video – Direct To Home Faucet

Companion Filter Installation Video – Direct To Included Faucet


Dimensions: 17.5″ L x 5.25″W x 14.75″ D



One of the chief benefits of the Aquametix filter is its capacity to remove the industrial version of fluoride from water. Fluoride occurs naturally in many water sources and is not harmful but the industrial version of fluoride infused into approximately 73% of American communities is an industrial pollutant which is also used an insecticide and pesticide.  The FDA, CDC and Water Quality Association of America refuse to acknowledge that the industrial version of fluoride is a poison. The majority of mainstream water treatment companies in America abide by the Water Quality Association stand that the industrial version of fluoride is healthy and necessary for children and adults thus few water companies will offer filtration for fluoride.


For well water we recommend this professional water test from Xpress Test.

If you are on a public water system, your water quality report is available online by going to the website of your public water system provider.

Here is an additional site for a limited water review:  EWG’S TAP WATER Database  (They don’t list fluoride).

3 reviews for Under Sink Companion Filter for Whole House Structured Water Systems

  1. Riley Taylor (verified owner)

  2. ANTWAIN WILSON (verified owner)

    Amazing product. I added this to my home I recently bought. The house was built in 1957 and partially connected to galvanized pipes. Prior to using the filter the water taste horrible, coffee was bitter. The water now is so clean and no taste or after taste. Interesting, when you fill a glass of water from the filter you can see the water not stale or lifeless like bottle or tap

  3. Allison C. (verified owner)

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