Highly effective at treating scale, corrosion and iron problems. These contain food-grade hexametaphosphate that dissolve slowly in water to prevent scale and rust build-up. PCC Series filter cartridges contain food-grade hexametaphosphate that dissolves slowly in water to inhibit scale and rust build-up. These cartridges are available in four feeder sizes with variable volumes of phosphate crystals. All materials are FDA grade. They are effective for treating scale, corrosion and iron problems for up to six months at various flow rates and feed concentrations.The PCC212 and PCC218 cartridges are designed to fit PENTEK #10 Standard or Slim Line filter housings. The PCC-1 cartridge is designed to fit in #10 Standard or Slim Line® filters only. The PCC-106 is an insert element that is placed in the center core of the cartridge. It is designed for use with standard 10" and 20" radial flow, sediment and carbon block double open-ended filter cartridges. This type of treatment 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.