Any lead on a great DI resin that doesn't exhaust as quickly as most? On my r/o units and after a 2 50 gallon water changes and two weeks worth of evap, I need to change out the cartridge. My evap level is around 2.5gallons a day.
I have 357 going in, 4 going to the resin and 0 after the resin, but I'm changing every couple to three weeks. Is this about normal? I'm using brs nuclear grade color changer.