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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Dervich Water Filters ®

Dervich Water Filters ®

* Dervich ® Compatible Replacement Water Filters & TFC Reverse Osmosis Membranes - 5 Stage System

3 vertical filter housings, one top mounted horizontal inline GAC carbon post filter and one top mounted standard size horizontal RO membrane housing.

  1. KX Matrikx ® 10/2 Carbon Block Water Filter # 10-250-190-975 Replacement-1000
    KX Matrikx ® 10/2 Carbon Block Water Filter # 10-250-190-975

    The KX 10/2 has been discontinued. If you order the KX 10/2 you will receive the GGN 10/2 Carbon Block Filter. 9 7/8" long X 2 1/2" diameter OD X 1 1/4" diameter ID. 25 per case, sold individually. Order a case and save even more.

    Learn How To Upgrade Your Reverse Osmosis Membrane Capacity

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    $17.99 Special Price $9.99 As low as $6.99
  2. PENTEK- #151121- Slim-Line Water Filter Housing Replacement - 1000
    Pentek # 151121 O-Ring For Slim Line Water Filter Housing Compatible With Culligan / Ametek / US Filter / Plymouth / Kleen Plus / American Plumber / Bruner & Many Other Brands
    Pentek # 151121 O-Ring For Slim Line Water Filter Housing Compatible With Culligan / Ametek / US Filter / Plymouth / Kleen Plus / American Plumber / Bruner & Many Other Brands. O-Ring For Slim Line Water Filter Housing. Buna-N FDA Grade. (Slim Line Housings Use A 3 1/2" diameter "O" Ring) Ametek # 151121 Same as Culligan OR-38 O-ring. Learn More
    $5.69 Special Price $4.99 As low as $3.00
  3. Pentek SW-1A # 150539 SW1 Slim Line Water Filter Housing Spanner Wrench
    Pentek SW-1A # 150539 SW1 Slim Line Water Filter Housing Spanner Wrench Compatible With Culligan / Ametek / US Filter / Plymouth / Kleen Plus / American Plumber / Bruner & Many Other Brands
    Pentek SW-1 # 150539 SW1 Slim Line Water Filter Housing Spanner Wrench Compatible With Culligan / Ametek / US Filter / Plymouth / Kleen Plus / American Plumber / Bruner & Many Other Brands. SW-1 Water Filter Housing Wrench. Fits 4" Slim Line Housings. (Slim Line Housings Have A 3 1/2" diameter "O" Ring) Ametek # 150294 Only for use in loosening filter housings, never to tighten. Overtightening may cause damage to the O-rings and make re-opening VERY difficult. Hand tighten only. Fits most standard style RO systems. Replaces 150294. For really stubborn filter housings our technicians will use two wrenches together for maximum power where one wrench might break or not do the job. Our techs know the tricks. Order New O-rings And Be Sure To Lube Them With Dow 111 Silicone Sealant To Prevent Leaks Learn More
    $9.99 Special Price $6.99 As low as $4.99
  4. GE Osmonics ® Purtrex PX-5-978 Sediment Replacement Water Filter # 93023
    GE Osmonics ® Purtrex PX-5-978 Sediment Water Filter # 93023
    GE Osmonics ® Purtrex PX-5-978 5 Micron Sediment Water Pre Filter. True-graded density pure polypropylene depth replacement water filter. # 93023 9 7/8" long X 2 1/2" diameter. 40 per case, sold individually. Order a case and save even more. Learn More
    $8.99 Special Price $5.99 As low as $3.99
  5. Pro Products Sani System Sanitizer
    Pro Products Sani System Sanitizer
    Pro Products Sani System Sanitizer. 0.25 or 0.5 fl. oz. concentrate. 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. 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. Sani-System is now NSF certified! This is the best sanitizing solution available anywhere! Stock up and save. Learn More
    $7.99 Special Price $4.99 As low as $2.49
  6. 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
  7. DOW FILMTEC - TW30-1812-100 HR RO Reverse Osmosis Membrane 170102- 1000
    Dow Filmtec ® TW30-1812-100 HR RO reverse osmosis membrane
    Dow Filmtec ® TFC 100 GPD RO reverse osmosis membrane - standard size 1.75" X 11.75" Extra fast recovery and high production flow rate.

    Learn How To Upgrade Your Reverse Osmosis Membrane Capacity

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    $129.99 Special Price $84.99 As low as $59.99
  8. TDS Water Meter Dual Mode Readings - DM2 HM Digital Professional Grade
    TDS Water Meter Dual Mode Readings - DM2 HM Digital Professional Grade - Easily Installs Inline - Very Simple To Use
    TDS Meter Dual Mode Readings - Professional Grade - Easily Installs Inline - Very Simple To Use. Measure the tap water coming in vs. the purified water going out of your system at any time. Use the meter to determine when the filters need to be changed. Highly efficient and accurate due to its advanced microprocessor technology. Displays TDS levels of the Feed Water and Product Water with in & out electrode probes. Auto-Off function conserves battery power. The unit shuts off automatically after 20 seconds. Dual Range - Measures from 0-999 ppm, with a resolution of 1 ppm. Learn More
    $69.99 Special Price $49.99 As low as $29.99
  9. HM Digital AP-1 AquaPro Water Quality Total Dissolved Solids Tester
    HM Digital AP-1 AquaPro Water Quality Total Dissolved Solids Tester
    HM Digital AP-1 AquaPro Water Quality Total Dissolved Solids Tester, 0-5000 ppm TDS Range, 1 ppm Resolution, +/- 2% Readout. HM Digital introduces its new AquaPro series, a line of handheld TDS/EC meters with a sleek design that's perfect for today's modern kitchen. The AquaPro digital water testers are the next generation for today's tech-savvy and health-conscience consumer. Learn More
    $42.95 Special Price $29.99 As low as $20.00
  10. Omnipure CL10RO-T/33-B 1/4''-  FNPT Inline GAC Filter -1000
    Omnipure CL10RO-T/33-B 1/4" FNPT Inline GAC Filter
    Omnipure CL10RO-T/33-B 1/4" FNPT Inline GAC Filter (granular activated carbon) Learn More
    $15.99 Special Price $11.99 As low as $9.99
  11. GGN-Faucet-AG-P-Chrome Air Gap Faucet-Long Reach-1000
    $39.99 Special Price $29.99
  12. 4 Gallon Reverse Osmosis Tank GGN-Tank-4-Pro-3.2
    4 Gallon Reverse Osmosis Tank GGN-Tank-4-Pro-3.2
    GGN-Tank-4 - 4 Gallon RO Reverse Osmosis Tank 1/4" NPT Threads. Stainless Steel connector. This is the perfect replacement tank for most residential RO Reverse Osmosis systems. Set Air Pre Charge To 7 psi With The Tank Empty Blue color. UPC #850901003491 Learn More
    $79.99 Special Price $49.99

Easy TDS Membrane Performence 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.


* Dervich ® is the registered trademark of Dervich, the manufacturer of Dervich ® brand water treatment equipment. The replacement filters and membranes listed above are not manufactured or endorsed by Dervich. Rather, these filters and membranes are manufactured by other companies. While these filters and membranes are compatible for use in Dervich ® brand water treatment equipment, we make no representation as to whether using these filters and membranes is consistent with the warranty and specifications applicable to Dervich ® equipment.