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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AvantaPure Reverse Osmosis Water Filters ®

AvantaPure Reverse Osmosis Water Filters ®


AvantaPure APPRO-50, RO-450 and Standard 4 Stage Reverse Osmosis System Compatible Replacement Water Filter Cartridges, TFC Reverse Osmosis Membranes, DIY Service Parts and HELP Guide.   


Choose your system shown below.


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.


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