Large selection of replacement water filters, reverse osmosis membranes, testing kits and water filter system repair parts. From one water filter or membrane to case quantity discounts.

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  1. WFO 500 - Compatible Fit Carbon Block Water Filters - 38476 - 2000
    WFO-500 - Sears Kenmore UltraFilter ® 150, 300, 350, 500 & 550, Whirlpool ® WHER 12 & WHER 18, EcoWater ® Compatible Fit Carbon Blocks 38476
    WFO-500 - Sears Kenmore Ultrafilter ® 150, 300, 350, 500 & 550 reverse osmosis system compatible replacement water filters twinpack (one pair). Replacement for Sears item #04238476000 model #38476. Compatible replacement filters for the Sears Kenmore UltraFilter ® Reverse Osmosis Drinking Water Systems # 38570, 38472, 38572, 38475 and 38575. Prefilter and post filter both included (two filters total). Also fits: Whirlpool ® WHER 12 & WHER 18, part #WHERF K002-87, EcoWater ® Compatible Carbon Block Water Filters. Sears Kenmore UltraFilter ® 150, 625.385700, 42-38476 Sears Kenmore UltraFilter ® 300, 625.384720, 42-38476 Sears Kenmore UltraFilter ® 350, 625.385720, 42-38476 Sears Kenmore UltraFilter ® 500, 625.384750, 42-38476 Sears Kenmore UltraFilter ® 550, 625.385750, 42-38576 Filters should be changed at least every 6 months. Order extra filter sets and save even more.
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    $39.99 Special Price $29.99 As low as $18.99
  2. WFO O-ring - Sears Kenmore UltraFilter ®, Whirlpool ®, EcoWater ® , Ecodyne ® compatible water filter replacement o-ring
    WFO-O-ring - Sears Kenmore UltraFilter ®, Whirlpool ®, EcoWater ® , Ecodyne ® compatible o-ring
    WFO-O-ring - Sears Kenmore UltraFilter ®, Whirlpool ®, EcoWater ® , Ecodyne ® compatible o-ring. Fits Sears Kenmore UltraFilter ® 150, 625.385700, 42-38476 Sears Kenmore UltraFilter ® 300, 625.384720, 42-38476 Sears Kenmore UltraFilter ® 350, 625.385720, 42-38476 Sears Kenmore UltraFilter ® 500, 625.384750, 42-38476 Sears Kenmore UltraFilter ® 550, 625.385750, 42-38576 Sears Kenmore ® 42-38456 Single Stage Deluxe Whirlpool ® WHER 12 Reverse Osmosis System Whirlpool ® WHER 18 Reverse Osmosis System, EcoWater ® 350 & 450. #E1000-228 --- 2 1/2" Diameter. Be sure to order Dow 111 Silicone Sealant to help prevent leaks.
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    $8.99 Special Price $5.99 As low as $3.99
  3. Pentek GAC-10 # 155109 GAC10 Taste & Odor Replacement Water Filter Cartridge
    Pentek GAC-10 # 155109 GAC10 Taste & Odor Replacement Water Filter Cartridge

    Pentek GAC-10 # 155109 GAC10 Taste & Odor Replacement Water Filter Cartridge Compatible With Culligan / Ametek / US Filter / Plymouth / Kleen Plus / American Plumber / Bruner & Many Other Brands Granular Activated Carbon Taste & Odor Water Filter. 9 3/4" long X 2 7/8" diameter. 12 per case, sold individually. Ametek # 155109 GAC Series cartridges effectively reduce unwanted tastes, odors and chlorine from your drinking water. They are designed to allow maximum contact between the water and carbon, ensuring maximum adsorption. 

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    $19.99 Special Price $11.99 As low as $9.99
  4. Pentek S1 # 155001 S-1 Sediment Replacement Water Filter Cartridge
    Pentek S1 # 155001 S-1 Sediment Water Filter Compatible With Culligan / Ametek / US Filter / Plymouth / Kleen Plus / American Plumber / Bruner & Many Other Brands
    Pentek S1 # 155001 S-1 Sediment Water Filter Compatible With Culligan / Ametek / US Filter / Plymouth / Kleen Plus / American Plumber / Bruner & Many Other Brands. S1 20 Micron Pleated Cellulose Sediment Water Filter. 9 3/4" long X 2 1/2" diameter. 24 per case, sold individually. Ametek # 155001 S1 series cartridges are economically priced and highly effective at reducing sediment particles down to 20 micron in size. Whole house or point of entry filtration to filter out sand, silt, dirt and rust particles that can restrict and plug finer filters, screens or equipment. Order a case and save even more.
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    $9.99 Special Price $6.99 As low as $5.69
  5. Pentek CW-F # 155186 CWF Sediment Replacement Water Filter Cartridge
    Pentek CW-F # 155186 CWF Sediment Water Filter Compatible With Culligan / Ametek / US Filter / Plymouth / Kleen Plus / American Plumber / Bruner & Many Other Brands
    Pentek CW-F # 155186 CWF Sediment Water Filter Compatible With Culligan / Ametek / US Filter / Plymouth / Kleen Plus / American Plumber / Bruner & Many Other Brands. Polypropylene String-Wound Sediment Water Filter, Fine. 10 Micron nominal. 9 7/8" long X 2 1/2" diameter. 24 per case, sold individually. Ametek # 155186 CW Series cartridges are manufactured from a durable polypropylene cored that is wound around a rigid polypropylene core. They are an economical solution to reduce fine sediment, including sand, silt, rust and scale particles. Order a case and save even more. Limited time offer for additional discounts for ordering in the Omnifilter packaging.
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    $6.99 Special Price $5.39 As low as $3.99
  6. PENTEK- WP-30 #155072 - String Wound Sediment Replacement Water Filter Cartridge- Lifestyle Photo 1-1000
    Pentek WP-30 # 155072 WP-30 Sediment Water Filter Compatible With Culligan / Ametek / US Filter / Plymouth / Kleen Plus / American Plumber / Bruner & Many Other Brands
    Pentek WP-30 # 155072 WP-30 Sediment Water Filter Compatible With Culligan / Ametek / US Filter / Plymouth / Kleen Plus / American Plumber / Bruner & Many Other Brands. WP30 Polypropylene String-Wound 30 Micron Sediment Water Filter. 9 7/8" long X 2 1/2" diameter. 24 per case, sold individually. Ametek # 155072 WP Series cartridges are manufactured from a durable polypropylene cord that is wound around a rigid polypropylene core. They are an economical solution to reduce fine sediment, including sand, silt, rust and scale particles. WP cartridges are wound in a precise pattern around the core providing a greater surface area. The result is a higher dirt-loading capacity and greater efficiency than standard wound cartridges like the CW. Order a case and save even more.
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    $9.99 Special Price $6.99 As low as $5.49
  7. Pentek P-5 # 155014 P5 Sediment Replacement Water Filter Cartridge
    Pentek P-5 # 155014 P5 Sediment Water Filter Compatible With Culligan / Ametek / US Filter / Plymouth / Kleen Plus / American Plumber / Bruner & Many Other Brands
    Pentek P-5 # 155014 P5 Sediment Water Filter Compatible With Culligan / Ametek / US Filter / Plymouth / Kleen Plus / American Plumber / Bruner & Many Other Brands. Spun Polypropylene 5 Micron Sediment Water Filter. 9 7/8" long X 2 1/2" diameter. 24 per case, sold individually. Ametek # 155014 P-Series cartridges are manufactured from 100% pure polypropylene fibers. The fibers have been carefully spun together to form a true gradient density from outer to inner surfaces. These cartridges are designed for purity. They will not impart taste, odor or color to the liquid being filtered when used within the recommended temperature limit. Also, the polypropylene construction provides superior chemical resistance and is not prone to bacterial attack. The coreless strength of the cartridges is achieved by sintering the many fibers into a solid matrix. Order a case and save even more.
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    $8.99 Special Price $5.99 As low as $3.99
  8. Pentek C-1 # 155002 C1 Taste & Odor Replacement Water Filter Cartridge
    Pentek C-1 # 155002 C1 Taste & Odor Water Filter Compatible With Culligan / Ametek / US Filter / Plymouth / Kleen Plus / American Plumber / Bruner And Many Other Brands
    Pentek C-1 # 155002 Compatible With Culligan / Ametek / US Filter / Plymouth / Kleen Plus / American Plumber / Bruner /OMNIFILTER And Many Other Brands C1 Taste & Odor Water Filter. Activated Carbon-Impregnated Cellulose 5 Micron Taste & Odor Water Filter. 9 3/4" long X 2 1/2" diameter. 24 per case, sold individually. Ametek # 155002 C Series cartridges offer an economical solution for all your general-purpose water filtration needs. Constructed of a carbon impregnated cellulose media, these dual-purpose cartridges filter out fine sediment particles and reduce unwanted taste, odor and chlorine from your tap water. A polyester reinforcement backing and external netting provide additional strength and dirt-loading capacity. These dual-purpose cartridges are well suited for a wide range of residential applications, and make excellent polishing filters when used in process or closed-loop streams. Order a case and save even more.
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    $11.99 Special Price $8.99 As low as $6.99
  9. Pentek R50-BB # 155053 Big Blue Pleated Reusable Replacement Sediment Water Filter Cartridge
    Pentek R50-BB # 155053 Big Blue Pleated Reusable Replacement Sediment Water Filter Cartridge

    Pentek R50-BB # 155053 Big Blue Pleated Reusable Replacement Sediment Water Filter Cartridge Compatible With Culligan R50-BBS, Ametek, US Filter, Plymouth, Kleen Plus, American Plumber, Bruner & Many Other Brands. Big Blue 50 Micron Reusable Pleated Polyester Sediment Replacement Water Filter. 10" long X 4 1/2" diameter. 8 per case, sold individually. Ametek # 155053. Same as Culligan R50-BBS. R Series cartridges are manufactured from a durable, non-woven and reusable polyester fabric that is suitable for a wide range of filtration uses. The media is pleated to maximize dirt holding capacity and extend the time period between changes or cleaning. R Series cartridges are resistant to both bacteria and chemical attack making them suitable for a variety of residential, commercial and industrial applications. Order a case and save even more.

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    $21.99 Special Price $15.99 As low as $13.99
  10. Pentek ECP5-BB # 255490 Replaces CP5BB #155184 Big Blue Sediment Replacement Water Filter Cartridge
    Pentek ECP5-BB # 255490 Replaces CP5BB #155184 Big Blue Sediment Water Filter Compatible With Culligan / OMNIFILTER / Ametek / Plymouth / Kleen Plus / American Plumber / Bruner & Many Other Brands
    Pentek ECP5-BB # 255490 Replaces #155184 CP5BB Big Blue Sediment Water Filter Compatible With Culligan / Ametek / US Filter / Plymouth / Kleen Plus / American Plumber / Bruner & Many Other Brands. Big Blue 5 Micron Pleated Cellulose-Polyester Sediment Water Filter. 10" long X 4 1/2" diameter. 8 per case, sold individually. Ametek #155184 Culligan CP-5BBS same as ECP5-BB (255490) CP Series cartridges are manufactured from a special formulation of resin-impregnated cellulose and polyester fibers. This construction provides high flow rates and dirt-holding capacities, while maintaining extremely low pressure drops. The media is pleated around a polypropylene core for added strength and the ends are immersed in a thermo-setting vinyl plastisol. Embedding and sealing each end of the pleat block in this fashion fuses the components together forming a unitized end cap and gasket. Order a case and save even more.
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    $27.99 Special Price $16.99 As low as $13.99
  11. Molykote-From DOw Corning- 111 Compound-6 Gram O-ring Silicone Lubricant & Sealant-Dow-111-5-gram-1000
    Dow Corning - Molykote ® 111 6 gram O-ring Silicone Lubricant and Sealant - Be sure to lube your O-rings to help prevent leaks.
    Dow Corning/Molykote ® 111 6 gram O-ring Silicone Lubricant and Sealant - 6 gram pillow pack. (like a ketchup packet) Great O-ring sealant and lubricant. FDA and NSF approved. (Do Not Use Petroleum Jelly As It May Break Down O-rings Or Housings) This is the same premium grade silicone sealant and lubricant used in underwater photography cameras, scuba gear and other underwater applications that simply can't afford leaks. Why not use the best for your reverse osmosis or drinking water filtration system?

    Dow 111 Silicone MSDS Safety Sheet

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    $5.99 Special Price $3.99 As low as $1.79
  12. Pentek DGD-5005 # 155357 Big Blue 5 Micron Replacement Sediment Water Filter Cartridge
    Pentek DGD-5005 # 155357 Big Blue 5 Micron Replacement Sediment Water Filter Cartridge
    Ametek / US Filter / Plymouth / Kleen Plus / American Plumber / Bruner & Many Other Brands Big Blue 5 Micron Dual Gradient Polypropylene Sediment Water Filter. 10" long X 4 1/2" diameter. 8 per case, sold individually. Ametek # 155357 DGD Series is manufactured from 100% pure polypropylene fibers and are sized for use in our Big Blue® filter housings. They are designed for purity and will not impart taste, odor or color to the liquid being filtered. Also, the polypropylene construction provides superior chemical resistance and is not prone to bacterial attack. The DGD Series advanced design combines selective "final filtration" with appropriate "pre-filtration." The larger diameter of the pre-filter, prefilter, pre filter reduces the particle load to the post filter, allowing it to operate at higher velocities. This increased depth provides for very high particulate reduction efficiencies and loading capacities. Order a case and save even more.
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    $24.99 Special Price $17.99 As low as $13.99
  13. Pentek GAC-BB # 155153 GACBB Big Blue GAC Carbon Replacement Water Filter Cartridge
    Pentek GAC-BB # 155153 GACBB Big Blue GAC Water Filter Compatible With Culligan / Ametek / US Filter / Plymouth / Kleen Plus / American Plumber / Bruner & Many Other Brands
    Pentek GAC-BB # 155153 GACBB Big Blue GAC Water Filter Compatible With Culligan / Ametek / US Filter / Plymouth / Kleen Plus / American Plumber / Bruner & Many Other Brands. Big Blue Granular Activated Carbon Water Filter. 10" long X 4 1/2" diameter. 8 per case, sold individually. Ametek # 155153 GAC Series cartridges effectively reduce unwanted tastes, odors and chlorine from your drinking water. They are designed to allow maximum contact between the water and carbon, ensuring maximum adsorption. The construction of the cartridge allows water to enter at one end and pass through the entire length of the cartridge, while an internal expansion pad minimizes channeling or bypass. Before the water exits the cartridge, a 20-micron post filter helps remove carbon fines and other suspended particles from the filtered water. Order a case and save even more.
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    $47.99 Special Price $35.99 As low as $31.99
  14. Pentek RFC-BB # 155141 RFCBB Radial Flow Whole House GAC Carbon Big Blue Water Filter Cartridge
    Pentek RFC-BB # 155141 RFCBB Radial Flow Big Blue Water Filter Compatible With Culligan / Ametek / US Filter / Plymouth / Kleen Plus / American Plumber / Bruner & Many Other Brands
    Pentek RFC-BB # 155141 RFCBB Radial Flow Big Blue Water Filter Compatible With Culligan / Ametek / US Filter / Plymouth / Kleen Plus / American Plumber / Bruner & Many Other Brands. Radial Flow Big Blue Carbon 25 Micron Water Filter. 10" long X 4 1/2" diameter. 8 per case, sold individually. Ametek # 155141. Same as Culligan RFC-BBS. RFC Series cartridges are constructed with a porous polypropylene outer shell and durable polypropylene end caps. Sandwiched between the outer shell and the core is a bed of granular activated carbon. The unique radial flow design offers the benefit of granular activated carbon filtration, such as low pressure drop, while at the same time eliminating the release of carbon fines commonly associated with GAC style cartridges. RFC Series cartridges are ideal for point-of-entry and other high flow rate applications. Order a case and save even more.
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    $84.99 Special Price $59.99 As low as $52.99
  15. Pro Products Sani System RO & Water Filtration System Sanitizer
    Pro Products Sani System RO & Water Filtration System Sanitizer
    Sani-System ® Pro Products is proud to introduce Sani-System, the first and only EPA product approved for sanitizing water softeners, RO units and Water Coolers. Alos NSF certified. Sani System is proven to kill 99.9% of E. coli, E. coli O157:H7, Staphylococcus aureus, Listeria monocytogenes and other harmful bacteria. It does not use chlorine, other oxidizers or acids that can harm water softener equipment parts. Use is simple; each dose comes in a pre-measured pouch. Just cut, pour and regenerate softener. No measuring, No mess! Sanitizing Equipment! Applications Interior Surfaces of Water Softeners, Reverse Osmosis (RO) Units, Ice Machines, Water Coolers, Water Holding Tanks and Pressure Tanks. Pro Products Sani System Sanitizer. 0.25 fl. oz. concentrate is perfect for your RO reverse osmosis drinking water system sanitizing..
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    $7.99 Special Price $4.99 As low as $2.99
  16. TDS Meter Inline Water Tester DM1 - HM Digital Dual Mode Reading
    TDS Meter Inline Tester- Dual Mode Reading - Easily Installs Inline - Very Simple To Use
    TDS Meter - Dual Mode - Installs Inline - Check the TDS level with the push of a button. Now you can easily check to make sure the water from your reverse osmosis system is top quality. Measure the tap water coming in vs. the purified water going out of your system at any time. Very easy installation. FEATURES Displays TDS levels of the feed water and product water with in & out electrode probes. Highly efficient and accurate due to its advanced microprocessor technology. Auto-Off function conserves battery power. The unit shuts off automatically after 10 minutes of non-use. Comes equipped with John Guest Quick-Connect T-fittings as shown. Installs quickly and easily. SPECIFICATIONS Range: 0-9990 ppm Accuracy: ±2% Always know if your RO membrane is performing correctly!
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    $49.99 Special Price $39.99 As low as $19.99
  17. Stainless Steel Designer Faucet for RO Reverse Osmosis & Drinking Water Filtration Systems
    Stainless Steel Designer Faucet for RO Reverse Osmosis & Drinking Water Filtration Systems
    Stainless Steel Designer Faucet for Drinking Water Systems. Beautiful designer faucet for beautiful kitchens. Air Gap / Non Air Gap design, single or three tube connection. Made of high quality 304 stainless steel incorporating a smooth operating ceramic disk element for extended reliability and quality. Great replacement upgrade for RO Reverse Osmosis and drinking water filtration systems. Lever Style Handle. High Reach Neck Design (12" / 305mm) 360 Degree Swivel Neck. Unique Protective Spout Tip which Prevents After Drip. 2 1/4" Base Diameter (57 mm) Drilled Hole Size Needed is 7/8".
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    $219.99 Special Price $99.99
  18. Air Pressure Gauge for Reverse Osmosis Water Accumulator Tanks -1000
    Air pressure gauge for reverse osmosis water accumulator tanks
    Air pressure gauge for reverse osmosis water accumulator tanks - Specially calibrated for reverse osmosis system tanks. Scale from 1 to 20 PSI. Large scale reading over small PSI range allows optimum accuracy. Just like car tires lose air pressure, so does the bladder of your reverse osmosis water accumulator tank. Improper tank air pressure will cause your system to operate improperly. This is a must for all reverse osmosis system owners.
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    $24.99 Special Price $17.99 As low as $12.99
  19. John Guest Super Speedfit Quick Connector - Male - Elbow
    John Guest ® Super Speedfit Quick Connector - Male - Elbow
    John Guest ® Super Speedfit Quick Connector - Male - Elbow - John Guest Super Speedfit Quick Connectors - Male - MNPT - Sold in pairs. Price is per pair. These fittings are manufactured in gray acetal copolymer with food grade nitrile ‘o’ ring, making them especially suitable for applications involving foodstuff and potable liquids like reverse osmosis drinking water. They are equally suitable for air and inert gasses and can therefore be used on CO2 lines, pneumatic applications, and vacuum. For more than a decade, John Guest has been supplying Super Speedfit fittings to the Water Purification market for drinking water applications in homes, restaurants and industry. John Guest products are listed with the WRC(UK), NSF(US) and SK(Germany). PI480821S , PI480822S , PI480823S , PI481222S , PI481223S
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    $8.99 Special Price $4.99 As low as $3.99
  20. Easy Tap Water Feed Valve for Water Filter Systems - 2000
    Easy Tap Water Feed Valve For Water Filter Systems 3/8" Feed Tube
    Easy Tap Water Feed Valve - High flow tap valve. Follow the pipe up from the shut-off valve toward faucet until you reach a coupling nut (may be all the way up to the faucet). Unscrew coupling nut. Screw brass easy tap onto previous location of coupling nut. Hand tighten and then one more complete turn with wrench. Re-attach water line coupling nut to easy tap. The valve on the side of the easy tap is the shut off valve for your new RO system. If the handle is turned clockwise all of the way, this is the "OFF" position for your new RO system. Counterclockwise all of the way is the "ON" position.
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    $16.99 Special Price $8.99 As low as $4.99

Easy TDS Membrane Performance Calculator
See If It is Time To Replace Your Membrane

Simply enter your Feed Water TDS and RO Water TDS into the boxes above and click "Submit". The percentage of TDS Rejection will be displayed. We normally recommend membrane replacement once you drop below 75%. This may vary in areas with high TDS in the feed water.

See our selection of TDS meters under Water Tests


Be sure to check our Parts Department for important parts such as TDS Testers For Reverse Osmosis Membranes, Replacement Tanks, O-rings , Filter Housing Wrenches, Faucets, Pumps, Fittings, UV Systems and more parts for your reverse osmosis pure water filtration system.   View maintenance and servicing tips online at our Installation & Trouble shooting Guide.





* Whirlpool the registered trademark of Whirlpool, the manufacturer of Whirlpool brand of under counter drinking water system filtration equipment and refrigerator water filters. The replacement water filter cartridges, reverse osmosis membranes, water tanks, faucets and repair parts listed above are not manufactured or endorsed by Whirlpool. Rather, these replacement filters, RO reverse osmosis membranes and DIY replacement parts are manufactured by other companies. While these replacement water filters, repair parts and reverse osmosis membranes are compatible for use in Whirlpool under counter reverse osmosis water filtration equipment, we make no representation as to whether using these water filter cartridges and RO reverse osmosis membranes is consistent with the warranty and specifications applicable to Whirlpool refrigerator filters or under sink drinking water system equipment.