RO/DI Help

[piranhaman00]

Hello all,

I have been having an issue with DI resin since I moved to a new place last year. Something has to be wrong and I want to try to solve the issue rather than continue to blow there DI Resin.

I attached an crude drawing detailing what I am discussing, below are specs, any ideas?

BRS water saver 200gpd
Input: 215 ppm
Pressure: 65-70psi
Chlorine/Chloramine tap is undetectable by HACH test strip
I am on city sewer so I figured city water but I am currently wondering if this is a CO2 issue from well water, the low chlorine content is hinting at that.

- Before entering DI, 8ppm, 96% rejection, acceptable as using the water saver will decrease rejection rate some, or so I read.
- I get about 60 gallons through each DI canister, I run 5 DI stages (5lb bag fills up 5 and I want to open and use entire bag a time)
- I have the TDS meter on the first two stages, after complete exhaustion the output after the second DI stage is 3ppm. This is strange, I thought it would go up to 8 after exhaust?
- The DI stages do not noticeably get more gallons the more down the line they are. Each canister makes approx 60 gallons, even after the second DI stage where it is apparently down to 3ppm.

Like I said above, I do not know if I am on city or well water, I am on city sewer so I suspect city water, this has to be a CO2 issue no? I know I could test this and I probably have the time now to try but any other thoughts? Any missing info?

 

[homer1475]

I would think if your on city water, Co2 wouldn't be an issue. Any treatment done to the water(all city supplied water has to go through some form of treatment) would negate the Co2.

I may be wrong though. I'm honestly not sure. Sorry couldn't be much more help

 

[Reefer1978]

I am guessing you are using mixed bed DI Resin? It has 2 different beads in it with different purpose, but only 1 is color changing. So even after it looks fully brown, it's still working - thus you are seeing 3ppm. With your setup, Randy (BRS) recommends splitting DI resins into separate components so you can see which one is actually consumed faster and only replace that one (won't help your 5 gallon at a time issue tho).

They shouldn't get better the further out they are. FIrst one is doing most work, until it's fully exhausted, and so on.

I think you can up your pressure a bit to 80.

 

[piranhaman00]

Apparently you can’t take a joke

I would think if your on city water, Co2 wouldn't be an issue. Any treatment done to the water(all city supplied water has to go through some form of treatment) would negate the Co2.

I may be wrong though. I'm honestly not sure. Sorry couldn't be much more help

You are correct, the thing I do not know if I am on city water or well, I am 95% sure its city, but this issue seems like CO2. But yes if its city water than CO2 cannot be the issue! Why I am struggling with the answer.

I am guessing you are using mixed bed DI Resin? It has 2 different beads in it with different purpose, but only 1 is color changing. So even after it looks fully brown, it's still working - thus you are seeing 3ppm. With your setup, Randy (BRS) recommends splitting DI resins into separate components so you can see which one is actually consumed faster and only replace that one (won't help your 5 gallon at a time issue tho).

They shouldn't get better the further out they are. FIrst one is doing most work, until it's fully exhausted, and so on.

I think you can up your pressure a bit to 80.

Yes mixed bed resin, forgot to mention.

Yes I should try using the anion and cation beds and see what is depleting faster.

The reason I mentioned the downstream resins, is because even when the first two appear to be fully exhausted, they are still removing 5ppm. So this must be an issue of one cation/anion being way more abundant and causing the resin to "exhaust" when its really only exhausted partially.

 

[homer1475]

Do you have a little blue tank somewhere in your water system coming into your home, or just a meter?

One of these somewhere in your home:

https://images.homedepot-static.com/productImages/f539da76-b210-41b3-bf38-d5c558669d03/svn/water-worker-well-pressure-tanks-ht86b-64_1000.jpg

 

[Reefer1978]

Yes mixed bed resin, forgot to mention.

Yes I should try using the anion and cation beds and see what is depleting faster.

The reason I mentioned the downstream resins, is because even when the first two appear to be fully exhausted, they are still removing 5ppm. So this must be an issue of one cation/anion being way more abundant and causing the resin to "exhaust" when its really only exhausted partially.

Yes that makes sense. Let's say it's anion that's only handling 60g per canister. As soon it's fully exhausted in in canister 1, canister 2 takes over and can only handle 60g. What I find very interesting is that it takes 3ppm of some element to fully exhaust 1 type of bead, and 5ppm of something else and second type of beads is still working.

 

[piranhaman00]

Do you have a little blue tank somewhere in your water system coming into your home, or just a meter?

One of these somewhere in your home:

https://images.homedepot-static.com/productImages/f539da76-b210-41b3-bf38-d5c558669d03/svn/water-worker-well-pressure-tanks-ht86b-64_1000.jpg

I live in a quadplex, I do not have one of those inside. And I am now certain I am on city water, I found it on my lease here. So most likely not CO2.

Yes that makes sense. Let's say it's anion that's only handling 60g per canister. As soon it's fully exhausted in in canister 1, canister 2 takes over and can only handle 60g. What I find very interesting is that it takes 3ppm of some element to fully exhaust 1 type of bead, and 5ppm of something else and second type of beads is still working.

Exactly! If it was the other way around it makes sense. Maybe a more charged element requires more resin capacity or something.

I will order some anion and cation and check them out, that must be the issue here.

Thanks!