Whole House Water Filter Purifier Sediment & CTO Carbon 3 High Flow 20" Systems 20" Clear Filter Housings with 3/4" Brass Ports, Mounting Brackets, Housing Wrenches and Filters Included 1st Stage: 20 Micron Sediment Filter. For particles such as sand, dirt, silt, and rust. To remove these particles it allows a better performance for the following Carbon Block filter. 2nd Stage: 5 Micron Carbon Block Filter. Removes chlorine, bad taste and odor, organic solvents and organic chemicals that contribute to bad taste and odor. 3rd Stage: 1 Micron Sediment Filter. For particles such as sand, dirt, silt, and rust down to 1 micron.