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Replacement Water Filters: Undersink

Don’t settle for a replacement under sink water filter cartridge that simply fits, find one designed and manufactured specifically for your under sink water filter system.

Discount Filter Store has one of the largest selections of undersink filter cartridges. With under sink filter cartridges available in over 15+ different filter medias, 8+ different sizes (5x2½ - 20x4½), and a wide variety of filter life’s ranging from 250 gallons to 50,000+ gallons, you’re guaranteed to find the under sink water filter system and/or replacement cartridges you need. Choose from hundreds of under sink water filter cartridges from some of the industry’s top brands including American Plumber, Crystal Quest, Pentek®, Culligan®, GE, Aqua-Pure®, Whirlpool®, and more.

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  1. 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
    $11.99 Retail Price:  $16.99
  2. 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
  3. 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
    $37.99 Retail Price:  $39.09
  4. 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
    $14.99
  5. 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
    $18.99 Retail Price:  $25.29
  6. 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 Retail Price:  $17.93
  7. 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 Retail Price:  $24.34
  8. P-250A Pentek Undersink Filter Set

    P-250A Pentek Undersink Filter Set

    Fits various brands of under-sink housings, including Culligan, Pentek, Ametek and American Plumber Learn More
    $23.99 Retail Price:  $31.27
  9. P-250 Pentek Undersink Filter Set

    P-250 Pentek Undersink Filter Set

    Fits various brands of under-sink housings, including Culligan, Pentek, Ametek and American Plumber Learn More
    $23.99 Retail Price:  $31.84
  10. RWC-5 Culligan Level 1 Undersink Filter Replacement Cartridge

    RWC-5 Culligan Level 1 Undersink Filter Replacement Cartridge

    Fits Culligan Fulflo, WC12, LCA, WS-12, and any brand of water filter system that uses standard 9 3/4 x 2 1/2 filter cartridges Learn More
    $12.99 Retail Price:  $17.24
  11. P5-D Culligan Level 4 Whole House Filter Replacement Cartridge (2-Pack)

    P5-D Culligan Level 4 Whole House Filter Replacement Cartridge (2-Pack)

    Fits Culligan HF-150, HF-160, HF-360, HF-365, and any brand of whole house water filter system that uses standard 9 3/4 x 2 1/2 filter cartridges Learn More
    $12.99 Retail Price:  $15.34
  12. P1-D Culligan Level 4 Whole House Filter Replacement Cartridge (2-Pack)

    P1-D Culligan Whole House Water Filter Replacement Cartridge (2-Pack)

    Fits Culligan HF-150, HF-160, HF-360 HF-365, and any brand of whole house water filtration system that uses standard 9 3/4 x 2 1/2 filter cartridges Learn More
    $12.99
  13. NCP-10 Culligan Whole House Filter Replacement Cartridge

    NCP-10 Culligan Whole House Filter Replacement Cartridge

    Fits any brand of whole house water filter system that uses standard 9 3/4 x 2 1/2 filter cartridges Learn More
  14. 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
    $33.99 Retail Price:  $38.51
  15. D-30 Culligan Level 2 Undersink Filter Replacement Cartridge

    D-30 Culligan 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
    $24.99

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