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BOROUX foundation.™ black filters


BOROUX foundation black filters are compatible with popular water filtration systems. They ensure years of reliable service with a lifespan of up to 6,000 gallons per filter (12,000 gallons per pair). The filters, equipped with Stem Saver technology, are reinforced for added durability during handling and cleaning.

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Key Features

The BOROUX foundation.™ filter is meticulously designed to seamlessly integrate with most gravity-fed water filtration systems including Berkey®, ProOne®, Alexapure Pro, Doulton, Patriot Pure Ultimate, and more. Whether it's refreshing your existing setup or initiating a new journey in water wellness, the filters have been crafted for broad compatibility with gravity-fed systems.

Full compatibility details here

Product information

We offer free shipping on all orders over $60 to the U.S. and Canada.

Boroux encourages customers to test products once they are received. For this reason, we accept returns of products in new or used condition. If you are not satisfied with the purchase for any reason, within 60 days of receiving the package, please get in touch with Customer Service.


The lowercase styling of 'foundation.' in our name speaks to the inherent simplicity of BOROUX. By choosing 'foundation', we reflect the straightforward and essential nature of our water filtration solutions—designed to be uncomplicated and accessible.


The period at the end of "foundation." symbolizes finality and completeness. It's a subtle way of saying that BOROUX foundation. is the definitive answer to water filtration needs. It's a complete solution, and there's nothing more to add – it's the final word in water filtration.


Just as the name "foundation." is grounded (with the period acting as an anchor), BOROUX is grounded in nature and its commitment to the environment. The name resonates with the brand's dedication to being a reliable foundation for filtered water solutions.

Rigorous Performance, Verified Data

Each filter created is a testament to a firm commitment to transparency. Undergoing meticulous testing procedures, the filters come with verified performance data that guarantee you receive water filtration you can count on. This product was designed exclusively to enhance municipal tap water. With each drop filtered, rest assured, you're enjoying the pinnacle of water filtration.

Reinforced Stem Saver™ Design

Recognizing the challenges of filter handling and maintenance, the BOROUX foundation.™ have been re-engineered with the innovative Stem Saver™. This advancement fortifies the most vulnerable part of the filter—its stem—against breakage, ensuring it can endure the rigors of regular cleaning and handling.

Uncompromising Quality, Direct to You

The BOROUX foundation.™ stands out by offering premium filtration directly to your doorstep. Eliminating middlemen ensures that each filter is a blend of top-notch quality and value. This direct-to-consumer approach provides superior hydration without the premium cost.

Designed for Universal Fit

Our filter is meticulously designed to seamlessly integrate with most gravity-fed water filtration systems. Whether it's refreshing your existing setup or initiating a new journey in water wellness, the filters have been crafted for adaptability.


Filter Capacity  Up to 12,000 gallons per pair depending on the quality of the influent water.*
View test results here.
Dimensions 2.75” x 2.75” x 9.75”
Composition Filters are comprised of a specialized blend of activated carbon. The BOROUX foundation filters contain silver, an antimicrobial agent, to prevent microorganisms from degrading the product itself. This filter is not intended to filter microorganisms.

Fits most gravity-fed water filtration systems and fluoride filters.

Warranty Coverage  BOROUX foundation filters are protected by a 1-year quality warranty. For further details on our warranty provisions, please contact customer support.
Maintenance  Scrub the BOROUX foundation filters every 3-6 months. Using an abrasive scouring pad, carefully scrub the surface of the filters for several minutes. DO NOT use soap or detergents on the filters. Re-prime the filters, install, and perform the red dye test to ensure proper installation of the filters. 
Replacement Filter  BOROUX foundation filter / Model BX·FND9·2
Box Includes
  • Two BOROUX foundation filters
  • Blue Priming Tool
  • Red Dye Test Solution
  • Tan Priming Tool
  • Product Insert

*Based on independent testing for the reduction of chlorine at 6,000 gallons per filter. While testing was performed under standard laboratory conditions, actual performance may vary. The contaminants or other substances removed or reduced by these filters are not necessarily in all users' water. Filter performance may vary based on local water conditions.

Compatible Water Systems

The BOROUX foundation.™ is designed with versatility in mind, fitting seamlessly with a range of systems. Below is a list of popular systems the filters fit in.

System Model
Berkey® Travel Berkey®
Big Berkey®
Berkey Light®
Royal Berkey®
Imperial Berkey®
Crown Berkey
AlexaPure® AlexaPure Pro®
Aquacera® Terra2
Doulton® PioneerTM SS4
Patriot Pure Patriot Pure Ultimate
ProOne® Big+
Big II
Waterdrop®  Waterdrop® King Tank

Don’t see your system listed? We’re here to help determine compatibility. Your feedback helps us expand our list of compatible systems. If you don't see your filtration system model, please send us an email at with the make, model, filter housing dimensions, and any other important specifications.

Frequently Asked Questions

How long do the filters last?

The filter lifespan will vary depending on the source water and contamination level. The recommendation for when to replace depends on several factors. For example, for filtering chlorine, the filters last for 12,000 gallons per pair. See recommendations for other contaminants.

How do the filters work?

BOROUX foundation filters work by absorbing and trapping contaminant molecules. The carbon attracts and absorbs molecules with a certain chemical charge. They stick to the carbon, like how a magnet attracts metal. The tiny pores of the carbon block are so small that they physically block and trap tiny particles. It's similar to a sieve or strainer.

What is the BOROUX filter made of?

A specialized blend of activated carbon.

More FAQS here

Customer Reviews

Based on 237 reviews
STEPHEN BIANCO (Eugene, United States)
Best Yet!

The Boroux filters are the best yet! Priced great too!

Thanks so much for your review! We love to hear that you're enjoying the quality of the BOROUX foundation. filters! We're so happy to be a part of your water wellness journey! Don't hesitate to reach out to our dedicated customer service team with any questions! Happy hydrating!

Nelba Maurin (Miami, United States)

Great service. Good quality.

Thank you! So happy that we met your expectations!

Thomas Kinate (Houston, United States)
Thoroughly impressed

Title says it, fast shipping, very well packaged, and the product is better than the Berkey it replaced.

Thanks so much for the review Thomas! We're so happy to hear that you're satisfied with the product and packaging quality! Thank you for choosing us to enhance your water hydration experience! Please don't hesitate to reach out to our dedicated customer service team if you have any questions or concerns. Happy Hydrating!

Courtney Englund (Providence, United States)

Excellent quality!

Thank you for your review! I am very happy that you are pleased with the quality!

Elizabeth Vandeberg (Kalispell, United States)

Very happy with my purchase. They fit my other filter just fine and the filtered water tastes great. Would purchase again. Thank you!

Thanks for the review! I am happy that the BOROUX foundation filters are compatible with your water system!

Our Story

Building on the legacy of 25 years in the water filter industry, BOROUX embraces innovation and ethical practices. We are committed to quality water. Every drop we filter is a testament to enhancing your well-being. Our dedication to better products, better practices, and better communication leads to you getting better water. BOROUX is the clear choice for hydration.

Learn More About Us


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