Pentek PCC-218 Scale Reduction Filter

http://www.waterfilters.net/Pentek-PCC218-Phosphate-Water-Filter.html
The Pentek PCC218 filters contain food-grade hexametaphosphate that dissolves slowly in water to inhibit scale and rust build-up. It is recommended for use with ice machines, coffee and vending machines, food service equipment, water heaters, air conditioning equipment and many other types of water processing equipment.It is not recommended for whole house water filtration. The PCC-218 is effective for treating scale, corrosion and iron problems for up to six months at various flow rates and feed concentrations. It works by keeping hardness particles separated so they cannot precipitate and form deposits when heated. It also forms a protective coating on all metal surfaces, safeguarding against acidity/alkalinity, hardness, chloride and other factors which effect the corrosion of water equipment and pipes. It works best with water having less than 15 grains of hardness, up to 1 ppm iron, and a ph between 6.0 and 9.0.