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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Ultima Reverse Osmosis Replacement Water Filters


Ultima ®*Reverse Osmosis Water Purification System Compatible Replacement Water Filters, Reverse Osmosis Membranes, DIY Service Parts and HELP Guides


Ultima VII 5 Stage Reverse Osmosis System , VIIC & Utima 7000 Reverse Osmosis Systems

Ultima VI 4 Stage Reverse Osmosis System

Ultima V 3 Stage Reverse Osmosis System

Ultima Heavy Residential - Commercial 5 Stage Reverse Osmosis Replacement Water Filters

Ultima -Microline - Clack Reverse Osmosis System

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.

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