50GPD Permeate Pump Reverse Osmosis System (OROS-50-PMT)


  • 5-stages of filtration
  • Permeate pump increases efficiency for low water pressure (30-50 psi)
  • 50 gallons per day (gpd) reverse osmosis membrane
  • Designed to fit inside most under-sink cabinets
  • Color-coordinated quick connect tube fittings

In stock

Limited Warranty: 1 Year

Olympia Water Systems Reverse Osmosis Water Filtration System is designed and tested to provide clean, high-quality drinking water at your home or business. The OROS-50-PMT includes a permeate pump that operates using built-up pressure from RO membrane wastewater (does not require electricity). The permeate pump increases RO system efficiency by filling the tank faster than a standard system, which makes it ideal for low-pressure homes and well water (30-50 psi).

This system does not include a separate Automatic Shut-off Valve, the Permeate Pump will automatically shut-off the RO system when the storage tank is full. However, without a separate Automatic Shut-off Valve installed, you may notice “TDS Creep”, which is a slight increase in TDS (total dissolved solids) readings under normal household operation. Infrequent system usage will increase the amount of “TDS Creep”. If you notice a large increase in TDS in your filtered water, you may want to consider adding an Automatic Shut-off Valve to the system. Please see our Technical Documents section on our FAQ page for instructions on adding a separate Automatic Shut-off Valve to this RO system.

DIY installation manual

Easy Install/Maintenance

Installing the system is easy with our step-by-step installation and maintenance guide with full-color photos.

NSF testing

Designed & Tested for Durability

In accordance with NSF/ANSI 42, the OROS-50 system was tested at 300 psi for 15 minutes, and 100,000 bursts of 150psi.

olympia customer support

Lifetime Customer Support

USA based customer service/technical support through email and phone.

NSF Certification

OROS-50-PMT has not been evaluated to NSF/ANSI standards 42 and 58. The OROS-50-PMT is the combination of OROS-50, which is a NSF certified system (NSF/ANSI 42 for the reduction of Chlorine, Taste and Odor and NSF/ANSI 58 for the reduction of Total Dissolved Solids), with OROS-PMT, a permeate pump that has not been evaluated to NSF/ANSI standards 42 and 58. *For details about our NSF listing, please visit our FAQ page.

High-Quality Water Purification

Our reverse osmosis systems remove impurities and contaminants from the water in your home or business to produce fresh, pure drinking water. Based on manufacturer testing, our reverse osmosis membranes remove the following:

  • Radium 226/228
  • Chromium (Hexavelent & Trivalent)
  • Selenium
  • Copper
  • Turbidity
  • Arsenic
  • Fluoride
  • Barium
  • Lead
  • Cadmium

Multi-Point Quality Control

quality control flow chart

Feed Water Pressure 50-100 PSI | 344-689 kPa
Feed Water Temperature 50-100° F | 5-38° C
Filtration System Dimensions 16” W x 7.5” D x 20” H
Tank Dimensions 12” W x 12” D x 18” H
Tank Capacity 3.2 Gallons
System Package Weight 27 lbs
UPC 859276006021

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30 Day Money-Back Guarantee

Olympia Water System products have a 30 day money-back guarantee from the date of purchase. All return shipping fees are the customer’s responsibility unless the return is due to manufacturer error or defect. For details on our Return Policy and Product Warranty please visit our Terms & Conditions and Warranty pages.


In-stock items will be shipped within 2-3 business days after your order has been placed. We currently only ship to addresses within in the United States (48 continental states, Alaska & Hawaii).