Search our shop

Phosphate Cartridge Insert

Phosphate center core cartridge insert for inhibiting scale and corrosion. Phosphate cartridge contains food grade hexametaphosphate slow dissolve crystals that inhibit scale and rust build up, thus preventing clogged and dripping nozzles caused by scale. Replace once there is no more crystals left. Installs in the center core of the #10 carbon filter facing up. 


  • Phosphate Center Core Insert: Slow release, food grade hexametaphosphate
  • Operating Temperature: 40 °F to 100 °F
  • Life: Up to 6 months
  • Flow Rate: 1-1.5 gallons per minute
  • Water Hardness: Up to 15 grains per gallon (256 ppm)


  • Not recommended for flow rates exceeding 1.5 GPM
  • WARNING: Do not use with water that is microbiologically unsafe or of unknown quality without adequate disinfection
  • CAUTION: Eye irritant. Contains sodium calcium hexametaphosphate. Avoid contact with eyes. In case of eye contact, flush with water for 15 minutes, seek medical attention. Keep out of reach of children.