I have a 3 stage DI. Cation - Anion - Mixed
Last year, I replace the Anion a few times. My source water is trash and nukes the Anion by 150-200 gal of finished water produced.
I recently ran an experiment with running mixed bed resin I purchase in bulk, in the Anion chamber with surprising results. I "exhausted" the resin after approx 150gal of finished water. Almost the same as using anion only. I saw nearly no change in the Cation chamber. I have left that "exhausted" resin in the 2nd chamber to see how long it will hold the 0 TDS coming out of it. I just produced another 50 gal of 0-2 TDS going into the 3rd chamber with resin that had completely changed color btw. So in my mind, not entirely exhausted. The 3rd chamber is the same mixed bed resin I've had for at least 9 months and barely any color change has occurred. I know it will start getting used much quicker now, but still has 0 TDS output.
Buying in bulk is cheaper. Also, not buying from BRS can save you more. I have not calculated the exact difference in price, but when I buy the Cation or Anion refills, I get them on sale for roughly $13/ea. You can get the bulk bags that do 6 cart changes for roughly $50-80, depending on brand and current sales.
My next experiment will be switching the Cation cart (after it's exhausted) to mixed bed also and run all three mixed bed carts. I'm curious how quickly they will get used up. If there isn't a noticeable difference, then my preference would be to only order mixed bed. Has anyone else tried this and what was your experience?
