The Pentair Pentek RFFE10-BB is a 10-inch Big Blue radial flow iron reduction cartridge designed for whole house water filtration. It reduces up to 3 ppm of dissolved iron from your water supply without the use of harmful chemicals, helping to improve water taste and reduce iron-related staining on fixtures, appliances, and plumbing. The radial flow design provides consistent contact with the iron reduction media for reliable performance.Install the RFFE10-BB on the main cold water line after the pressure tank for whole house coverage. For optimal filtration results, pair it with a sediment pre-filter and a post-carbon cartridge. This cartridge is designed for water supplies with pH above 7.0, silica below 100 ppm, manganese below 1 ppm, and no iron bacteria or hydrogen sulfide present.The RFFE10-BB fits all standard 10-inch Big Blue and heavy duty filter housings that accept 10-inch x 4.5-inch cartridges. At 3 ppm iron concentration, the cartridge provides approximately 26,000 gallons of capacity, or about 104 days of use for a household of four. Replace the cartridge when you notice a return of metallic taste or iron staining.