Recently we received an email which accused us of having bias when it comes to the reverse osmosis water treatment systems we mention. Apparently we can’t discuss the things we like on our own web site.

Who knew? Certainly not us! Ha ha.

Having said that, in hindsight we do realize that we have done a not-so-great job when it comes to offering up options for NSF/ANSI certified reverse osmosis water treatment systems… so today we’d like to bring a family of three NSF/ANSI certified reverse osmosis systems manufactured by Watts Premier, Inc. to your attention.

The Watts 315, Watts 415 and Watts 525 have all tested and certified to NSF/ANSI Standard 58 for the reduction of Arsenic (Pentavalent), Barium, Cadmium, Chromium (Hexavalent), Chromium (Trivalent), Copper, Cyst, Fluoride, Lead, Radium 226/228, Selenium, Turbidity, and TDS — and each one has a price tag under $300.


Watts 315
Reverse Osmosis System
Meets NSF/ANSI Standard 58
Watts 415
Reverse Osmosis System
Meets NSF/ANSI Standard 58
Watts 525
Reverse Osmosis System
Meets NSF/ANSI Standard 58

The main difference between the three units? From what we can tell the main difference lies in the number of filtration steps in the units:

  • Watts 315 RO System — 3 levels of filtration: 5 micron Sediment Pre Filter 10″. Granular Activated Carbon Block Pre Filter 10″. Extruded Carbon Filter (CTO).
  • Watts 415 RO System — 4 levels of filtration: 5 micron Sediment Filter for suspended solids. Granular Activated Carbon Filter to improve taste and odor while reduce heavy chlorine presence. High Quality TFC Membrane. In-Line Granular Activated Carbon Post Filter to give a final polishing to water for improved taste and odor.

  • Watts 525 RO System — 5 levels of filtration: 5 micron Sediment Filter for suspended solids. Granular Activated Carbon Filter to improve taste and odor while reduce heavy chlorine presence. Carbon Block Pre Filter. High Quality TFC Membrane. In-Line Granular Activated Carbon Post Filter to give a final polishing to water for improved taste and odor.

We hope that by presenting a few more affordable reverse osmosis water filters that have earned NSF Certification (see this page for more details on these units’ NSF qualifications) we have helped a few people become more familiar with the sorts of compounds and potential drinking water contaminants that reverse osmosis systems can reduce/remove.