Description The OneFlow Plus Carbon Block Water Filter Replacement is to be used only as a replacement filter for the OneFlow Plus Whole House system. This salt-free scale reduction and water filtration system uses a commercially trusted, physical water treatment technology to keep scale from forming on pipes and reducing appliance life, along with a high-capacity water filter to remove foul tastes, odors, and sediments for better tasting tap water. A single, compact unit with dual cartridges replaces a space-consuming water softening system and water filtration system – using no salt, chemicals, and electricity. OneFlow Plus system is certified by the Water Quality Association (WQA) to NSF/ANSI Standard 372 for lead free. The carbon block used in the OFPRFC carbon filter is certified to NSF/ANSI 42. Watts Water Technologies OneFlow Anti Scale Media is certified by the Water Quality Association (WQA) to NSF/ANSI Standard 61. Chemical-free scale reduction and protection converts hard minerals into soft particles preventing build up inside pipes and does not add or remove anything from water, allowing useful minerals such as calcium, potassium, and magnesium to remain High-capacity, 20-micron water filter removes chlorine taste and odor while reducing sediment without chemicals or salt which is better for the environment leaving nothing but quality drinking water Chlorine reduction up to 50,000 gallons (189,000 liters) at 3 GPM (11.34 lpm); dirt holding capacity up to 2.2 lbs.