DI Resin Mixed Bed Color Changing Bulk Media Quantity ::9 x 5# bag (36 x 10" refills) Illustrations Diagrams Instructions : How to Change the UV unit should Illustrations Diagrams Instructions : How to Change Filters Complete hardware kit for adding a second membrane to your existing RO or RODI system: 1) standard membrane housing 1) a FF1100 flow restrictor Mixed bed DI resin is a combination of anion and cation resins used in water purification to remove both positive and negative ions Such systems are typically designed without meters and rely on the changing color of the DI mixed bed resin to indicate exhaustion