Excerpt from Build thread: slight variation on DI and DEE - GASSING!

[rockstarta78]

Following. My DI depletes so fast that it got my head spinning.

 

[Reef Jeff]

Ingenious way to extend the cartridge...I love that kind of thinking. This is a pretty common problem which I solved it a different way...not better, just different. I bought a bulk box of mixed DI resin from a wholesaler when it was on sale. Paid $75 for 2 cubic feet. Then I bought an empty cartridge. I fill it with the bulk DI resin and put that in between the membrane and the high quality DI cartridge. The first cartridge grabs the excess TDS when the float lets the water start moving through the RO unit and it pretty much strips all the TDS before it hits the good cartridge. I change the first one 3x's more often (typically once a month) and as soon as I see any increase in TDS on the output I change it again. The final cartridge lasts 3-4 months this way. I have enough of the cheap mixed resin to do this for years. My source water is softened so that makes all this work a lot better.

 

[bbak]