Is deionization resin (color changing) rather sensitive to being exhausted over time (if it sits within the filter housing with water in it for a long time), or is it mostly dependent on how much water runs thru it?
Agreed, and naturally occurring CO2 in the tap will burn thru DI resin faster as well. I make about 50 gallons RO/DI about every two weeks with high CO2 at the tap(well water), incoming TDS 10-20 depending on time of year. The anion resin last about 18 months, cation last forever, about 3 years now on my water.Yes how much water is run through it and compounded by the TDS of the incoming water to the DI resin.