Discount Water Filters and Air Filters at Discount Filter Store.com

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Undersink Water Filters & Systems

Transform the water served from your tap or faucet into a premium quality beverage with an under sink water filter.

With over 250+ under sink water filter systems and undersink replacement filters available in a wide range of flow rates, colors/finishes, prices, and filter life’s, we’ve got an undersink filter for every home. Choose from some of the best under sink water filters including the Crystal Quest 7 Stage Under Sink Fluoride Water Filter System, the Culligan® Level-4 Easy Change Undersink Drinking Water System, and the 3M Filtrete™ Undersink Advanced Water Filter System.

Not sure, which under the sink water filter is right for your home? Give us a call 1-800-277-3458; our experts will help you choose the perfect under sink filter to address all of your water quality concerns, no matter how monumentous they may seem.

Note: All of our under sink filters and under sink water filter systems are backed by our 100% Price Match Guarantee. Meaning if you find a particular under sink water filter for less than our listed price, we’ll match the competitors lower price. Shopping for home water filters has never been easier.

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  1. TIER1-GAC-10 Pentek Undersink Replacement Cartridge by Tier1

    TIER1-GAC-10 Pentek Undersink Replacement Cartridge by Tier1

    Fits standard 9 3/4-inch x 2 1/2-inch replacement filter cartridges. Learn More
    $12.99
  2. D-25 Culligan Under Sink Water Filter

    D-25 Culligan Under Sink Water Filter

    Fits under sink filter systems that use 10 x 2.5-inch filters Learn More
  3. P-250 Pentek Comparable Under Sink Water Filter Set Tier1

    P-250 Pentek Comparable Under Sink Water Filter Set by Tier1

    Fits various brands of under-sink housings, including Culligan, Pentek, Ametek and American Plumber Learn More
    $21.99 MSRP:  $41.99
  4. AP117 3M Aqua-Pure Comparable Whole House Sediment Water Filter by Tier1

    AP117 3M Aqua-Pure Comparable Whole House Sediment Water Filter by Tier1

    Fits most whole house water filter systems that uses standard 10 x 2-1/2 filter cartridges Learn More

    As Low As $0.00 Per Filter

  5. D-250A Culligan Comparable Under Sink Water Filter Set by Tier1

    D-250A Culligan Comparable Under Sink Water Filter Set by Tier1

    Fits various brands of under-sink housings, including Culligan, Pentek, Ametek and American Plumber Learn More

    As Low As $0.00 Per Filter

  6. P-250 Pentek Comparable Under Sink Water Filter Set by Tier1

    P-250 Pentek Comparable Under Sink Water Filter Set by Tier1

    Fits various brands of under-sink housings, including Culligan, Pentek, Ametek and American Plumber Learn More

    As Low As $0.00 Per Filter

  7. P-250A Pentek Comparable Under Sink Filter Set by Tier1

    P-250A Pentek Comparable Under Sink Filter Set by Tier1

    Fits various brands of under-sink housings, including Culligan, Pentek, Ametek and American Plumber Learn More

    As Low As $0.00 Per Filter

  8. WHKF-DB1 Whirlpool Comparable Under Sink Water Filter by Tier1

    WHKF-DB1 Whirlpool Comparable Under Sink Water Filter by Tier1

    Fits various brands of under-sink housings, including Culligan, Pentek, Ametek and American Plumber Learn More

    As Low As $0.00 Per Filter

  9. WHKF-DB2 Whirlpool Comparable Under Sink Water Filter by Tier1

    WHKF-DB2 Whirlpool Comparable Under Sink Water Filter by Tier1

    Fits various brands of under-sink housings, including Culligan, Pentek, Ametek and American Plumber Learn More

    As Low As $0.00 Per Filter

  10. D-25 Culligan Comparable Undersink Replacement Cartridge by Tier1

    D-25 Culligan Comparable Undersink Replacement Cartridge by Tier1

    Fits standard 9 3/4-inch x 2 1/2-inch replacement filter cartridges. Learn More

    As Low As $0.00 Per Filter

  11. WCC Amercian Plumber Comparable Undersink Replacement Cartridge by Tier1

    WCC Amercian Plumber Comparable Undersink Replacement Cartridge by Tier1

    Fits standard 9 3/4-inch x 2 1/2-inch replacement filter cartridges. Learn More

    As Low As $0.00 Per Filter

  12. CC-10 Pentek Comparable Undersink Replacement Cartridge by Tier1

    CC-10 Pentek Comparable Undersink Replacement Cartridge by Tier1

    Fits standard 9 3/4-inch x 2 1/2-inch replacement filter cartridges. Learn More

    As Low As $0.00 Per Filter

  13. OmniFilter RS12-SS6-05 Polypropylene Sediment Filter

    OmniFilter RS12-SS6-05 Polypropylene Sediment Filter

    Standard 10 inch by 2.5 inch size fits many common filter housings Learn More
    $4.99 MSRP:  $11.99
  14. W5CIP American Plumber Undersink Filter Replacement Cartridge (2-Pack)

    W5CIP American Plumber Undersink Filter Replacement Cartridge (2-Pack)

    Fits American Plumber W38-PR and most standard size water filter housings Learn More
    $21.99 MSRP:  $24.34
  15. WCC American Plumber Undersink Filter Replacement Cartridge

    WCC American Plumber Undersink Filter Replacement Cartridge

    Fits American Plumber W38-PR and most standard size water filter housings Learn More
    $19.99 MSRP:  $26.44
  16. CB1 OmniFilter Undersink Filter Replacement Cartridge

    CB1-SS6-S06 OmniFilter Undersink Water Filter Cartridge

    For use in any brand of undersink water filtration systems that use 9 3/4-inch x 2 1/2-inch water filter cartridges Learn More
    $34.99 MSRP:  $47.99
  17. CB3 OmniFilter Undersink Filter Replacement Cartridge

    CB3-SS6-06 OmniFilter Undersink Filter Replacement Cartridge

    Fits any brand of undersink water filter system that uses standard 9 3/4 x 2 1/2 filter cartridges Learn More
    $50.99
  18. CQE-RC-04002 Crystal Quest PLUS Multi-Stage Replacement Filter Cartridge

    CQE-RC-04002 Crystal Quest PLUS Multi-Stage Replacement Filter Cartridge

    Fits most standard housings that accept 10-inch x 2.5-inch water filter cartridges Learn More
    $49.49 MSRP:  $66.99
  19. D-10-TWIN Culligan Level 1 Undersink Filter Replacement Cartridge (2-Pack)

    D-10A Culligan Level 1 Undersink Filter Replacement Cartridge (2-Pack)

    Fits Culligan US-550, US-600, US-600A, SY-2000, SY-2100, and any brand of water filtration system that uses standard 9 3/4 x 2 1/2 filter cartridges Learn More
    $13.99 MSRP:  $17.93
  20. D-15 Culligan Level 1 Undersink Filter Replacement Cartridge (2-Pack)

    D-15 Culligan Level 1 Undersink Filter Replacement Cartridge (2-Pack)

    Fits Culligan US-550, US-600, US-600A, RO-3000, RO-3500, RVF-10 and any brand of water filtration system that uses standard 9 3/4 x 2 1/2 filter cartridges Learn More
    $19.59 MSRP:  $29.99
  21. D-20A Culligan Level 1 Undersink Water Filter Replacement Cartridge

    D-20A Culligan Level 1 Undersink Filter Replacement Cartridge

    Fits Culligan US-550, US-600, US-600A, RO-2127, RO-3000, RO-3500, and any brand of water filtration system that uses standard 9 3/4 x 2 1/2 filter cartridges Learn More
    $15.39 MSRP:  $23.99
  22. D-250A Culligan Undersink Filter Replacement Cartridge Set

    D-250A Culligan Undersink Filter Replacement Cartridge Set

    Fits the Culligan SY-2300, SY-2300S and SY-2650 systems and any brand of undersink water filter system that uses standard 9 3/4 x 2 1/2 filter cartridges Learn More
    $31.99 MSRP:  $46.99
  23. D-28 Culligan Level 1 Undersink Filter Replacement Cartridge

    D-28 Culligan Level 1 Undersink Filter Replacement Cartridge

    Fits Culligan US-550, US-600, US-600A, and any brand of water filter system that uses standard 9 3/4 x 2 1/2 filter cartridges Learn More
  24. D-30 Culligan Level 2 Undersink Filter Replacement Cartridge

    Culligan D-30 Level 2 Undersink Filter Replacement Cartridge

    Fits Culligan US-550, US-600, US-600A, SY-2000, SY-2100, and any brand of water filtration system that uses standard 9 3/4 x 2 1/2 filter cartridges Learn More
    $25.69 MSRP:  $37.99
  25. D-40 Culligan Level 4 Undersink Water Filter Replacement Cartridge

    D-40 Culligan Level 4 Undersink Water Filter Replacement Cartridge

    Fits Culligan US-550, US-600, US-600A, and any brand of water filter system that uses standard 9 3/4 x 2 1/2 filter cartridges Learn More
    $34.99 MSRP:  $50.99

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