Should new resin bead in the Demineralizer Bottle be both purple and yellow?
Color of demineralizer resin.
With the Demineralizer Bottle, 177 and 473 mL Capacity (Catalog number/Order code 1429900 and 2184600) half the resin beads are normally yellow, and half are purple. The purple beads contain an indicator that changes to yellow when the resin is saturated. The yellow beads work the same but do not change color when saturated. When all of the beads are yellow, discard them and replace with fresh resin.