DSC04919Harn R/O Systems, Inc. has forty years of experience in the design, manufacture, installation and maintenance of reverse osmosis water treatment systems, producing systems for numerous applications, with capacities of up to 12 million gallons per day.  Our success with these large, sophisticated systems is due in large part to our ongoing commitment and involvement with pilot systems.

Harn R/O Systems, Inc. has designed and manufactured numerous pilot systems, including brackish R/O, membrane softening, membrane filtration (micro and ultra filtration) and seawater desalination. From 1,000 gallons per day (GPD) production capacity to over 20,000 GPD, pilot units can be provided to test single elements or full scale system design utilizing full length vessels in two or three stage configurations. Our understanding of the goals of pilot studies and our experience with the operation of pilot systems makes us uniquely qualified to design and manufacture pilot systems that are reliable, “operator-friendly”, and provide quality data.

Pilot studies are invaluable to establish and optimize design parameters such as feed pressure, recovery, flux, chemical dosages, and recommended cleaning frequencies. Pilot studies may also be necessary to fulfill regulatory requirements such as the EPA Information Collection Rule. 

Pilot unit installation and start-up services are available. Technical assistance and data evaluation will be provided during the study. Harn R/O staff has many years of experience in pilot studies, design and manufacturing of reverse osmosis and membrane softening treatment systems. Our technical staff will be personally involved during the study, enabling the customer to utilize the resources of our experience for the benefit of the project. 

Please allow us to support you in evaluating your pilot study requirements. Please contact us if you like to lease or purchase a pilot unit.


  • Maximum testing and monitoring flexibility provide through comprehensive instrumentation and sample ports

  • Built on durable fiberglass and steel epoxy-painted frames, on wheels

  • Chemical systems and cartridge filter pretreatment included

  • Pretreatment chemical injection facilities included

  • Membrane autopsy services


  • Additional pre- or post-treatment equipment

  • Portable cleaning system

  • Full remote access and data logging capabilities

Past Pilot Users


bluesquare 01 Membrane Filtration   greensquare 01 Seawater   reddiamond 01 Brackish R/O and Membrane Softening

Brackish R/O and Membrane Softening


  • City of Industry, California
  • Grimes, Iowa
  • Elizabeth City, New Jersey
  • City of Industry, California
  • City of Brighton, Colorado
  • City of Dunedin, Florida
  • City of Boynton Beach, Florida
  • City of Jupiter, Florida
  • City of Plantation, Florida
  • City of Englewood, Florida
  • City of Sarasota, Florida
  • City of Venice, Florida
  • Sarasota County, Florida
  • Acme Improvement District, Florida
  • Collier County, Florida
  • Florida Water Services
  • Deltona, Florida
  • Hutchinson, Kansas
  • Houston, Texas
  • Clay Rural Water Association
  • Wakonda, South Dakota
  • Florida Water Services
  • Marco Island, Florida
  • City of North Miami, Florida
  • DuPage County, Illinois
  • City of Wyoming, Illinois
  • City of Kewanee, Illinois
  • City of Elmwood, Illinois
  • City of Ottawa, Illinois
  • City of Brimfield, Illinois
  • Elizabeth City, New Jersey
  • Dare County, North Carolina
  • Suffolk County North Carolina
  • Grand Forks, North Dakota
  • City of Mt. Pleasant, South Carolina
  • City of Farmington, Illinois
  • City of Palm Coast, Florida
  • Pasquotank County, North Carolina
  • Hardinsburg, Kentucky
  • Phoenix, Arizona
  • Toulon, Illinois
  • Jupiter, Florida
  • Hutchinson, Kansas
  • Palm Coast, Florida
  • Logan Township, New Jersey
  • Riverside, Iowa
  • Tampa, Florida
  • Winterset, Iowa
  • Jacksonville, NC
  • Englehard, NC
  • Anamosa, Iowa
  • Poweshiek, Iowa
  • Hartley, Iowa
  • North Port, Florida
  • Pella, Iowa
  • Concord, California
  • Miami, Florida
  • Burnt Store, Florida
  • Woodbine, Iowa
  • San Antonio Water Systems, Texas
  • Everest, Kansas
  • Atkins, Iowa
  • Dickinson, South Dakota
  • Allegan, Michigan
  • Manatee County, Florida
  • Xenia Rural Water, Iowa
  • Delaware, Ohio
  • Weeksville, North Carolina
  • Perquimans County, North Carolina
  • San Angelo, Texas
  • Douglas County, Kansas
  • Pinellas County, Florida
  • Labelle, Florida
  • Craven County, North Carolina
  • North Lee County, Florida
  • Abilene, Texas
  • Chase County, Kansas
  • Monterey, California
  • Lawrence, Kansas
  • North Liberty, Iowa
  • West Liberty, Iowa
  • El Paso, Texas
  • Washington, Iowa
  • Grimes, Iowa
  • Industrial Customer, for AECOM
  • Seminole Tribe of Florida, Brighton
  • San Angelo, TX

Membrane Filtration


  • Abilene, Texas
  • Lawrence, Kansas
  • Marco Island, Florida
  • Numerous sites for Aquasource
  • City of Sarasota, FL
  • Manatee County, FL
  • Alameda County Water District, CA
  • Monterey, California
  • Abilene, Texas
  • Clearwater, Florida
  • Lawrence, Kansas
  • Fort Worth, Texas



  • Collier County, Florida
  • Grand Bahamas Industrial application
  • The Affordable Desalination Water Collaboration, Port Hueneme, CA
  • And numerous other sites for ADC
  • US Filter for Tampa Bay Water Seawater Retrofit
  • Dow Filmtec Seawater Pilot