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-20BB Replacement Granular Activated Carbon Filter by Tier1

    TIER1-GAC-20BB Replacement Granular Activated Carbon Filter by Tier1

    The TIER1-GAC-20BB replacement granular activated carbon filter by Tier1, is universal for a variety of water filter housings sized 20x4.5 inches. Learn More
    $37.99
  2. 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

  3. 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

  4. 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

  5. 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

  6. WRC25HD20 American Plumber Comparable Granular Activated Carbon Filter by Tier1

    WRC25HD20 American Plumber Comparable Granular Activated Carbon Filter by Tier1

    The WRC25HD20 American Plumber comparable replacement granular activated carbon filter by Tier1, is universal for a variety of water filter housings sized 20x4.5 inches. Learn More

    As Low As $0.00 Per Filter

  7. GAC20-BB Pentek Comparable Granular Activated Carbon Filter by Tier1

    GAC20-BB Pentek Comparable Granular Activated Carbon Filter by Tier1

    The GAC-20BB Pentek comparable replacement granular activated carbon filter by Tier1, is universal for a variety of water filter housings sized 20x4.5 inches. Learn More

    As Low As $0.00 Per Filter

  8. AP817-2 Aquapure Comparable Granular Activated Carbon Filter by Tier1

    AP817-2 Aquapure Comparable Granular Activated Carbon Filter by Tier1

    The AP817-2 Aquapure comparable replacement granular activated carbon filter by Tier1, is universal for a variety of water filter housings sized 20x4.5 inches. Learn More

    As Low As $0.00 Per Filter

  9. RFC20-BB Pentek Comparable Granular Activated Carbon Filter by Tier1

    RFC20-BB Pentek Comparable Granular Activated Carbon Filter by Tier1

    The RFC20-BB Pentek comparable replacement granular activated carbon filter by Tier1, is universal for a variety of water filter housings sized 20x4.5 inches. Learn More

    As Low As $0.00 Per Filter

  10. FXB20RFL Filtrex Comparable Granular Activated Carbon Filter by Tier1

    FXB20RFL Filtrex Comparable Granular Activated Carbon Filter by Tier1

    The FXB20RFL Filtrex comparable replacement granular activated carbon filter by Tier1, is universal for a variety of water filter housings sized 20x4.5 inches. Learn More

    As Low As $0.00 Per Filter

  11. 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
  12. WGCHD American Plumber Undersink Water Filter Replacement Cartridge

    WGCHD American Plumber Undersink Filter Replacement Cartridge

    Fits American Plumber W10-PR and W15-PR and most other heavy duty water filter housings Learn More
    $34.99 MSRP:  $48.29
  13. P10-5 Tier1 Polypropylene Sediment Filter

    P10-5 Tier1 Polypropylene Sediment Filter

    Sized 4 7/8 x 2 1/2 inches Learn More
    $3.99 MSRP:  $5.74
  14. P1-5 Tier1 Sediment Filter Cartridge

    P1-5 Tier1 Sediment Filter Cartridge

    Sized 4 7/8 x 2 1/2 inches Learn More
    $4.99 MSRP:  $8.34

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