The 5-micron CTO coconut shell carbon block filter is more effective than other forms of carbon in that it is finely ground up carbon packed into a solidified block. This means they have a higher density than other types of carbon filters and are therefore more effective in removing their targeted contaminants. The carbon block filter knocks out bad tastes and odors, removes over 90% of sediment and chlorine from the water, and is highly effective on organic chemicals (VOCs) like pesticides, herbicides, and industrial chemicals. The second filter has an iron and manganese reducing filter – also great for the plethora of heavy metals found in well water sources. The FM25B iron and manganese reducing filter are only included with the iSpring WGB22BM (and WGB32BM), as it is not needed for most municipal water supplies that the WGB22B targets. Protect Your Family and Household Appliance from Iron, Manganese, and More Our filter (FM25B) is specially designed for iron & manganese removal, reducing iron MAX 3. 0 ppm down to 0. 01 ppm and manganese MAX 1. It lasts up to 3 times longer than greensand due to the catalytic media not being consumed in the process. The filter set also removes sediment, chlorine, rust, pesticides, herbicides, industrial solvents, VOCs, and various other contaminants. DIY Installation and Maintenance Refer to our manual and our helpful YouTube videos for easy DIY installation. The 20 x 4. 5 filter cartridges have a minimum impact on water flow (up to 15 GPM) and require minimum maintenance. Our filter set fits standard 20 x 4. 5 housings, including brand name models. Top-Notch Quality The first stage high capacity polypropylene sediment filter can achieve filtration down to 5 microns. The second stage CTO Carbon Block filter is made of high-quality coconut shell carbon for maximum filtration efficiency and filter life. Both are tested by an independent third party to meet NSF/ANSI standards. Both filters have a capacity of 100, 000 gallons of water, enough to supply a family of four with clean water for a full year. Please Note The cartridges are individually wrapped to ensure freshness. Please unwrap the cartridges before use. For well/pond water with very high iron/manganese. Unlike an RO membrane, the filters don’t reduce Total Dissolved Solids (TDS), and instead, keep healthy minerals in your water. If you are interested in a filter that removes TDS, consider our iSpring Reverse Osmosis (RO) systems.