Applied Membranes Whole House Water Filter Replacement Kit for 20" Big Blue 3-Stage Iron Reducing Water Filter Following the recommended schedule to replace the water filters ensures that you are receiving high quality water and optimum performance from your whole house water filtration system. Applied Membranes Replacement Filter Packs take the guesswork out of scheduling and ordering replacement water filters. Original replacement for FA-320BB-5CI-1 whole-house water filter for removing iron & manganese. These standard sized filters can be used to upgrade most 3-stage whole house water filters using 20" Big Blue housings. Simply exchange the system's existing cartridges with the Applied Membranes filters to receive superior performance and safety benefits immediately. 3 Stages of Powerful Water Filtration Included [STAGE 1] 5 Micron Sediment Filter: Removes Dirt, Rust, Sand, Dust, Silt, and other particles from water down to 5 microns. This protects your plumbing & appliances and extends the life of the carbon filters. The graded pore structure uses the entire depth of the filter - capturing larger particles in the outer layers and decreasing in size as it reaches the center. This maximizes the dirt holding capacity, giving more time between changeouts. [STAGE 2] Iron & Manganese Filter: Iron Reduction from 3 to >0.01ppm and Manganese Reduction from 1 to >0.01ppm. Safe for drinking water applications. Filters up to 50,000 gallons of water with 3ppm Iron. [STAGE 3] HP Carbon Block Filter with Advanced Chemical Adsorption: Rated at >240,000 gallons for chlorine reduction, Applied Membranes high performance carbon filter removes residual chlorine, chloramine, VOCs, and 100s of other harmful chemical contaminants commonly found in tap water. Made with 100% coconut shell carbon.