It is my understanding that single bed media may be regenerated, but I would think that mixed bed would not be feasable due to the conflicting regeneration requirements Butch
I would guess that it is most likely the case, unless you can separate the media individually or it is mechanically separate but in one "container". For example if it were layered (with maybe some kind of sheet barrier that was completely water permeable or even porous, but with pores smaller than the resin beads) and you could separate the layers to do them individually. I have to guess because I may be a chemist, but it's not my specific area of expertise (and haven't used it for a very long time).-kby
What I use is the Purolite brand mixed media that changes color with use... once it turns golden brown you replace it. I get very long service life with mine (over a year) and I'm able to maintain a consistent 0ppm TDS output
I think it is pretty much the "Industry" standard for RO/DI use now. The only thing I did change was to mount the DI container vertically. This prevented channeling of the beads per my own experience and a Purolite service memo. The volume of the beads definitely shrink with use.
The original factory typical RO/DI horizontal mounting required constant "topping off" with more beads to prevent channeling, it was a joke. A top down flow path seems to be the best.