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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Water-Safe RO-20B Water Filters ®

Water-Safe RO-20B Water Filters ®

Water-Safe RO-20B ® 3 stage compatible replacement water filters and CTA RO reverse osmosis membranes 

1st Stage  5 Micron Sediment Pre Filter - Replace Every 3-6 Months 
2nd Stage 16 GPD CTA Reverse Osmosis Membrane
3rd Stage 5 or 10 Micron Post Filter - Replace Every 12 Months 


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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.


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