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Filmtec Dow Reverse Osmosis Residential Membranes ®

Filmtec Dow Reverse Osmosis Residential Membranes ®

Dow Filmtec ® TFC Replacement Reverse Osmosis RO Membranes

Standard Size

Find out how to increase the GPD capacity size of your membrane

Dow Filmtec commercial membranes

  1. Regular Price: $89.99

    Special Price $56.99

    As low as: $37.99

    Dow Filmtec ® TW30-1812-24 24 GPD TFC RO reverse osmosis membrane - standard size 1.75" X 11.75" Part # 93430

    Learn How To Upgrade Your Reverse Osmosis Membrane Capacity

    Learn More
  2. Regular Price: $99.99

    Special Price $59.99

    As low as: $39.99
    Dow Filmtec ® TW30-1812-36 TFC 36 GPD RO reverse osmosis membrane - standard size 1.75" X 11.75" Part # 80719 Learn More
  3. Regular Price: $84.99

    Special Price $69.99

    As low as: $54.99
    Dow Filmtec ® TW30-1812-50 TFC 50 GPD RO reverse osmosis membrane - standard size 1.75" X 11.75" Part # 80722 Learn How To Upgrade Your Reverse Osmosis Membrane Capacity Learn More
  4. Regular Price: $119.99

    Special Price $74.99

    As low as: $49.99
    Dow Filmtec ® TW30-1812-75 (BW60-1812-75) TFC 75 GPD RO reverse osmosis membrane - standard size 1.75" X 11.75" Part # 114731 Learn More
  5. Regular Price: $129.99

    Special Price $84.99

    As low as: $59.99
    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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  6. Regular Price: $33.99

    Special Price $19.99

    As low as: $14.99
    Premium inline reverse osmosis membrane flow restrictor - Our in-line capillary flow restrictors are simple to install. Simply push the 1/4" poly tube firmly into the quick connectors and you are done. Be sure that you order the flow restrictor size to match your reverse osmosis membrane size. Arrow on side points toward the drain. Very simple to install. Learn More
  7. Regular Price: $34.99

    Special Price $19.99

    As low as: $16.99
    Standard size RO reverse osmosis membrane housing - 90° Ports with 1/8" FNPT Threads - Includes New O-rings and 3 90° 1/4" Jaco Fittings For 1/4" O.D. Tube. Upgrade to the optional John Guest Quick Connectors. The end with a single port is the inlet feed water. On the end with two ports the center port is the permeate (product) water. The offset port is the brine (waste). Learn More
  8. Regular Price: $17.99

    Special Price $9.99

    As low as: $8.49
    O-rings For Standard Style RO Membrane Housing. Pair of O-rings for standard style reverse osmosis membrane housings. Learn More
  9. Regular Price: $17.99

    Special Price $9.99

    As low as: $6.99
    Wrench To Fit Standard Size Membrane Housings. Easily open those stubborn reverse osmosis membrane housings. Learn More
  10. Regular Price: $129.99

    Special Price $89.99

    TW30-1812 Stainless Steel RO Membrane Housing - High detail and quality. This high end Stainless Steel RO Membrane Housing fits standard residential TW30-1812 RO membranes, which is the most common size of reverse osmosis membrane for home RO systems. This SS Membrane Housing is the finest quality housing we have ever seen for residential RO systems. Food Grade 304 Stainless Steel. Learn More
  11. Regular Price: $5.99

    Special Price $3.99

    As low as: $1.79
    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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  12. Regular Price: $7.99

    Special Price $4.99

    As low as: $2.49
    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
  13. Regular Price: $49.99

    Special Price $37.99

    As low as: $17.99
    TDS Meter - Tester. The Only Way To Know If Your Reverse Osmosis RO Membrane Is Performing Correctly - Tests for TDS - Total Dissolved Solids. A Must For All RO System Owners. Compare Incoming Feed Water To Treated Water - Replace Membrane If Less Than 80% of TDS Is Being Removed - The lower the TDS level in the water, the more efficiently your body's cells actually get hydrated by the water that you drink. The higher the TDS levels in the water, the greater the probability of harmful contaminants that can pose health risks or hinder the absorption of water molecules on the cellular level. Simple to use for Reverse Osmosis membrane monitoring. We really like this tester and think that anyone who wants to know about the quality of their water should have one of these TDS Meter Testers to monitor their RO membrane. Learn More
  14. Regular Price: $49.99

    Special Price $39.99

    As low as: $19.99
    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! Learn More

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 (total disolved solids) 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.   Let the tap water and reverse osmosis water run for a few seconds before drawing your sample.

See our selection of TDS meters under Water Tests.  Knowing the rejection rate is the only wat to know if it is time to replace your reverse osmosis membrane.


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.


* Dow Filmtec ® is the registered trademark of Dow, the manufacturer of Dow Filmtec ® brand water treatment equipment. The replacement filters and membranes listed above are not manufactured or endorsed by Dow Filmtec. Rather, these filters and membranes are manufactured by other companies. While these filters and membranes are compatible for use in Dow Filmtec ® 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 Dow Filmtec ® equipment.