WP-ST6DM Six-Stage RO System
Reverse Osmosis

WP-ST6DM Six-Stage RO System

Availability: In Stock
  • Vendor:Premier a Watts Brand
$ 334.35

The high efficiency Premier Six Stage Reverse Osmosis System provides high quality water at an affordable price. This new Reverse Osmosis System is designed with two parallel 75 gallon per day reverse osmosis membranes that provide faster, more efficient Reverse Osmosis water production compared to a single 150 GPD membrane. A larger, space efficient, 3 gallon storage tank is included to ensure Reverse Osmosis water is always available on demand. The Premier Six Stage Reverse Osmosis System is perfect for home or office, as well as hydroponics and aquatic tanks.

The WP-ST6DM Reverse Osmosis Filtration System uses a 6-Stage Filtration based upon separate treatments.

  • Sediment - A 5 Micron Sediment Filter traps sediment and other particles like dirt, silt and rust which affect the taste and appearance of your water.
  • Carbon (2) - Runs through 2 stages of 5 Micron Carbon Block Filters reducing Chlorine, and other materials that cause bad taste and odor.
  • 75 GPD Membrane (2) - Runs through 2 stages of 75 GPD Semipermeable Membranes removing TDS, Sodium and a wide range of contaminants such as Chromium, Arsenic, Copper, and Lead.
  • Carbon In-Line (GAC) - A high quality In-Line Granular Activated Carbon (GAC) Final Polishing Filter is used after the water storage tank to remove any remaining chlorine or other chemicals that cause bad taste or odor before being dispensed.

California Prop 65 Warning CALIFORNIA PROP 65 WARNING: This product can expose you to chemicals including lead which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.

Click here to download your 521934 WP-ST6DM Manual.

For the return policy details, please click here.


Parameter Minimum Maximum
Operating Temperatures: 40°F (4.4°C) 100°F (37.8°C)
Operating Pressure: 40 psi (2.81 kg/cm2) 100 psi (7.03 kg/cm2)
pH Parameters: 2 11
Iron: N/A 0.2 ppm
TDS (Total Dissolved Solids): N/A <1800 ppm
Turbidity: N/A <5NTU
Hardness: N/A 10 Grains Per Gallon


*The WP-ST6DM Reverse Osmosis System will operate with hardness over 10 grains per gallon but the membrane life may be shortened.


  • Reverse Osmosis Filtration System
  • 4-Gallon Storage Tank
  • Module with one Full Set of Filters including (2) 75 GPD Membranes Pre-Installed
  • Standard Chrome, Non-Air-Gap Faucet
  • Adapt-A-Valve™
  • Drain  Saddle
  • Manual


Product Dimensions

  • Rack and Cartridges (15.7" W x 20.3" H x 6.9" D)
  • Tank (19.3" H x 9.4" D)
  • Model # WP-ST6DM. Item # WP521934

(Due to the individual fittings the exact measurements may vary slightly.)

This warranty will be void if defects occur due to failure to observe the following conditions:

  • The Reverse Osmosis System must be hooked up to a potable municipal or well cold water supply.
  • The hardness of the water should not exceed 10 grains per gallon, or 170 ppm.
  • Maximum incoming iron must be less than 0.2 ppm.
  • The pH of the water must not be lower than 2 or higher than 11.
  • The incoming water pressure must be between 40 and 100 pounds per square inch.
  • Incoming water to the RO cannot exceed 100 degrees F (40 degrees C.)
  • Incoming TDS/Total Dissolved Solids not to exceed 1800 ppm.
  • Do not use with water that is microbiologically unsafe or of unknown quality without adequate disinfection before or after the system

This warranty does not cover any equipment that is relocated from the site of its original installation. This warranty does not cover any charges incurred due to professional installation. This warranty does not cover any equipment that is installed or used outside the United States of America and Canada.

To see additional information and details regarding the warranty, please click here.

Your Rights Under State Law

Some states do not allow limitations on how long an implied warranty lasts, and some states do not allow the exclusion or limitation of incidental or consequential damages, so the above limitations or exclusions may not apply. This warranty gives you specific legal rights, and you may have other legal rights which vary from state to state.