The RFFE20-BB cartridge is designed to provide an easy and effective method of reducing iron from water, which greatly improves the taste. This cartridge helps to eliminate the orange and brown stains often found in sinks, toilets, tubs and other plumbing fixtures. RFFE20-BB reduces the possibility of damage to pipes and water heaters and reduces up to 3 ppm dissolved iron. It adds no harmful chemicals to the water, making it completely safe for drinking water applications. The RFFE20-BB cartridge should be installed on the main cold water line after the pressure tank or water meter. For best results, pre-sediment and post-carbon treatment is recommended. Iron Level Filter Life 250 GPD (4 ppl) 125 GPD (2 ppl) 75 GPD (1 person) 3 ppm 26,000 Gal. 104 Days 208 Days 416 Days 2 ppm 40,000 Gal. 160 Days 320 Days 640 ays 1 ppm 80,000 Gal. 320 Days 640 Days 1280 Days 0.5 ppm 160,000 Gal. 640 Days 1280 Days N/A Recommended Operating Conditions pH 7.0 Silica 100 ppm Manganese 1 ppm Iron 3 ppm Iron Bacteria None Hydrogen Sulfide None