OneFlow® Residential Anti-Scale Solutions

All models on this page include OneFlow® anti-scale technology. When recommending a system your installer will consider household water usage, available space, and added water treatment options.



OFPSYS - Up to 10 gallons per minute

Prevent scale while improving the taste of water. The OneFlow+ system is a dual cartridge-based system with a radial flow 20 micron carbon block cartridge which reduces sediment, chlorine taste and odor, and an integrated OneFlow scale prevention cartridge. The OneFlow+ is a compact size making it ideal for installation in small spaces.

  • Replace OneFlow cartridge every 3 years and carbon block cartridge every year

Introducing OneFlow +

Installing your OneFlow +


ETREATWCS - Up to 12 gallons per minute

In addition to scale prevention, the E-Treat Water Conditioning System contains coconut shell-activated carbon that improves water taste and reduces odors, chlorine, and organic substances.

  • Offers all the benefits of OneFlow®
  • Produces great-tasting water
  • Reduces chlorine and organic substances often found in drinking water
  • Replace OneFlow media every 3 years and carbon media every 2 years

Whole House Anti-Scale Systems

OFRES - Up to 16 gallons per minute

These systems are installed at the point of entry to treat both the hot and cold water. For systems requiring more than 16 gallons per minute, refer to the Commercial Systems page.

  • Replace OneFlow media every 3 years

Tankless Water Heater Anti-Scale System

OFTWH-R - Up to 6 gallons per minute

This easy to install unit is designed to extend the lifespan of water heaters.

  • Reduces scale and improves the efficiency of water heaters
  • Helps to prevent harmful mineral build-up on heating elements
  • Replace cartridge every 2 years

Watts offers a full line of filtration, reverse osmosis and ultraviolet treatment systems in addition to scale prevention. They can be installed to treat the whole house or under a sink at the point of use. Ask your installer about water quality testing if you have concerns about the quality of your water.