DI Resin

[Jamie]

Hi All,

How often do you have to replace your DI Resin? I've had my BFS Chloramine Special unit for 3 months and I'm already getting over 20 ppm final product. I know it is the DI. My TDS going in is 600, after the membrane it's 37, and after the DI it's 22-25. I have made maybe 200 gallons at most. Do you think this is a normal absorption rate of DI? 200 gallons of 37ppm water?

[Big_Pun]

that's kinda weird maybe the water pressure isn't high enough how many gallons an hour s the ro membrane

[Jamie]

The water presure is good...between 45 and 50 psi at the membrane. I called Russ at BFS and he was very helpful. Apparently, each DI canister is good for trapping about 5000ppm give or take. At 200 gallons of 30+ ppm going in, that's over 6000ppm...so I am due for new DI. I think I'm going to go with a dual DI resin set-up to avoid slow TDS creep as the DI wears out. I will have them in series with a "T" in between the DI resin canisters so I can test the DI output after the first DI canister but before the 2nd. When the TDS starts to go up after the first, I'll know I need to change out that resin...but I will be covered by the second canister to keep TDS at 0. What I'll do upon replacement is move the 2nd canister's resin cartridge to the 1st canister's spot and have the fresh resin on stand-by in the #2 position to repeat the process.

Ordering my stuff right now.

[txav8r]

Contact Russ at BFS. He is the expert on the subject and is very helpful. You can post a question on his forum http://www.maast.org/forums/forumdisplay.php?f=54 or contact him here:
Contact Buckeye at 513-312-2343 (tele) or 513-231-4600 (fax) or sales@buckeyefieldsupply.com

[Jamie]

I think you just missed my earlier post. Russ is a really nice guy...great customer service.

[txav8r]

DOH!

I must have been looking up Russ' info when you posted that.
Good idea with the 2 DI canisters. I might have to try that.

[Jamie]

Thanks, I just ordered my stuff. I already have a spare plastic housing, so I just needed to get a refillable DI cartridge to put inside it. I also ordered 5lbs of resin. I should be good for well over a year now.

[Pennies2Cents]

Have you tried to do a routine flush on your unit?

[Jamie]

I don't think a flush is necessary. The rejection rate of my membrane is up to snuff...somewhere in the vicinity of 95%. Corpus water is some of the worst around. I've already seen a few resignations from the water quality managers because it gets so bad. My TDS out of the tap is around 620ppm. The RO membrane takes it down to 30-35ppm, and the DI resin takes care of the rest. Now that I know that a standard 10" X 2.5" DI cartridge can handle approximately 5000ppm of TDS, I will sort of have an idea of when to change out the resin to keep the system running optimally. I'm still going with two DI canisters though.

[CoryDude]

David (aka Solid) has Corpus h20. Look at his set up:

http://www.maast.org/forums/showthread.php?t=49005

[Pennies2Cents]

Well if it helps, we did the flush and it lowered the reading of the final product from 54 to 32. It was then that we it was time to replace all filters. (Our Choice) And bamm back at 0. :) Maybe if you change just the RO filter that may help as well.

[Jamie]

Hmmmm....interesting that changing your filters brought your TDS down to zero. I was hoping I wouldn't be changing filters for at least another 3 months. And RO membranes should be good fo over a year.

Based on what my numbers were from new though...I think my filters are still good to go. My TDS downstream of the membrane has not changed.

I have read that both DrMark and Soild are using a "silicate" removing DI resin in their second DI canister. I'm not familiar with this. I'll have to give one of them a call.