Lately I've been having a little issue with algae, even after adding a 15-piece CUC, PWC, and keeping the lights off for a day or 2. That's when I went to my RO/DI, since I hadn't really checked it in a while.
003ppm! Oh heeeellllno!
I ordered replacement filters immediately to get that thing back to 000pm. I took some pictures so I could remind myself when to recognize the filters getting too ugly.
Ugly Carbon and Sediment filters next to the fresh guys (Jan 15, 2012)
Check out that resin! Are you serious!?
I know you may not believe me, but after almost a year of seeing this thing everyday in my garage, I didn't notice it turning colors or losing much volume. Here's the recently refilled DI chamber compared to the old 1:
So I set up an alarm in AquaPlanner to replace these babies in about 9 months. With tap water at ~485ppm (+/-25) and pressure at 25psi, it's as long as they last.