Question: What’s the difference between color-indicating DI resin and non color-indicating DI resin?

Answer: Color changing DI resin has a water soluble dye that will change its color and thereby yield a general indicator when the resin is exhausted (depleted). We offer both color indicating (i.e., Color-Changing) resin, and non color indicating resin (Nuclear). They are identical resins except for the dye. Bear in mind that the color-changing feature as a very general indicator only. You can commonly continue to use the resin (depending on usage) for weeks or months after it begins to change color. It is best to use a TDS meter to monitor how well the resin is performing, and when it’s time for a new resin refill. Although there are no known harmful effects of the dye, we would suggest that you use the non-color changing dye if you have the availability of a TDS meter.