This upflow cartridge has two media's for optimum effectivess against hard water scale build up.  KDF 55 and Slow Phos!

Effective up to 30 grain per gallon of hardness, Filter cartridge and media are NSF/ANSI Standard 42 & 60 for potable water applications.

Change cartridge every 12 months,  1.67 gpm, 4" x 14".