Crystal Quest Eaglesorb Anti-Scale is a saltless, non-chemical, hard water treatment medium. When using Eaglesorb ES3, nothing is added to the water. Calcium carbonate crystals formed by ES3 remain dissolved in water. ES3 prevents scale buildup and dissolves previous buildup. ES3 eliminates scaling on the surface of heat sources, fixtures and appliances. Pre-treatment is required for iron, manganese, copper, oil, hydrogen sulfide, phosphate and chlorine above 3 PPM. ITEM NUMBER SIZE FLOW RATE CAPACITY (<100 PPM HARDNESS) CQE-RC-04113 2-7/8” x 9-3/4” 1.5 gpm (5.6 lpm) 805 grains/13,760 ppm* CQE-RC-04114 2-7/8” x 20” 2.5 gpm (9.4 lpm) 2,080 grains/35,600 ppm* CQE-RC-04115 4-5/8” x 9-3/4” 3 gpm (11.4 lpm) 2,080 grains/35,600 ppm* CQE-RC-04116 4-5/8” x 20” 6 gpm (15.2 lpm) 5,200 grains/70,200 ppm* Construction Materials Fiber Media Cation Resin End Caps Polystyrenen Post-Filter Spun Polypropylene Outer Casting Polystyrene Expansion Pad Polypropylene Gasket Buna-N (Top) Temperature Rating 40°F to 145°F (4.4°C to 62.8°C) *Capacity is an estimate only and is dependent on influent water contaminants and filter usage.