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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Filbur Water Filters ®

Filbur Water Filters ®

Filbur ® compatible replacement water filters & reverse osmosis membranes.

FMRO4J, FMRO4G, FMRO5J, FMRO5G, FMRO5GP

Water filters replacement kit for 4 stage Filbur ® reverse osmosis systems.  Includes FMRO4J, FMRO4G & others.

Water filters replacement kit for 5 stage Filbur ® reverse osmosis systems.  Includes FM5O4J, FMRO5G, FMRO5GP & others.

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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.


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