Does to much di resin do harm?

[Tommy's Reef]

I get 2 tds coming into my first canister of di resin, but I have 2 di resin canisters.
Am I stripping to much of the water with 2 canisters!
Is there a such thing as to clean of water?

 

[lpsouth1978]

Nope, you can't get it too clean. You want to have 0 TDS. This means you have 100% pure water, no contaminants!

 

[Tommy's Reef]

So I could probably do without the second canister then?

 

[lpsouth1978]

Probably. I get 4 TDS going into my resin, but I also have 2 canisters. To me this just means that I don't have to change the resin as often. No harm in keeping them both running.

 

[35ppt]

Redacted

 

[fishguy242]

The first one will deplete faster and the second will ensure 0 TDS water. Once the first is fully depleted you refill it and swap them. No waste.

/At least that's what I remember from some BRS video. I've just got one.

its late sorry,what he said

 

[Randy Holmes-Farley Verified Community Expert]

So I could probably do without the second canister then?

If you get 2 tds out of the first one, you need to replace it. That 2 ppm TDS water may be worse for the tank than the incoming water to that DI.

It never hurts in any scenario to have more DI cartridges in series.

IMO, it is a good idea to use them like this:

1. have two mixed bed DI.
2. Use the first one until the TDS is nearly the same after the first one as the water coming to it. Then remove it.
3. Move the second DI into the first DI slot.
4. Put a new DI in the second (last) position).

This way you can fully use the DI and never have TDS above 0 ppm.

 

[hotashes]

@Randy Holmes-Farley trust all is well my friend, FYI I believe the OP suggests the 2TDS is entering first DI pod. May be worth a quick look back to make sure. Stay safe

 

[Randy Holmes-Farley Verified Community Expert]

@Randy Holmes-Farley trust all is well my friend, FYI I believe the OP suggests the 2TDS is entering first DI pod. May be worth a quick look back to make sure. Stay safe

Ah, yes. Thanks. No need to change it then, but I would still use two.

 

[hotashes]

@Randy Holmes-Farley as were on topic of leaving the first DI pod in place until it hits incoming TDS number, My TDS from membrane to first DI pod is 5-6, on what output TDS from pod one do you suggest in my situation prior to it hitting pod 2 DI?

Thanks, Ash.

 

[Randy Holmes-Farley Verified Community Expert]

@Randy Holmes-Farley as were on topic of leaving the first DI pod in place until it hits incoming TDS number, My TDS from membrane to first DI pod is 5-6, on what output TDS from pod one do you suggest in my situation prior to it hitting pod 2 DI?

Thanks, Ash.

Well, something like 3-4 ppm TDS. Enough drop to know it isn't dead quite yet.

 

[hotashes]

Thank you, as always.

 

[Gordonm]

The first one will deplete faster and the second will ensure 0 TDS water. Once the first is fully depleted you refill it and swap them. No waste.

/At least that's what I remember from some BRS video. I've just got one.

My second di canister depletes faster than the first..

 

[lpsouth1978]

My second di canister depletes faster than the first..

This should NOT be the case. If your second canister is depleting faster, then the first canister is probably not packed tight enough and water is channeling through the resin, bypassing it. Ideally, there should be nothing for the second canister to remove until the first has been depleted. That is if you are using mixed bed resin in both canisters. different story if you have Anion resin in one canister and Cation in another.

 

[Dr. Jim]

I wondered, too, if it is possible to have too many DI canisters. I have 6: two Cation; two Anion; two Mixed. (BSR products). When the first of each type gets close to depletion, it is removed with the second one being moved to the first position and a new one added to the second position.

 

[Gordonm]

This should NOT be the case. If your second canister is depleting faster, then the first canister is probably not packed tight enough and water is channeling through the resin, bypassing it. Ideally, there should be nothing for the second canister to remove until the first has been depleted. That is if you are using mixed bed resin in both canisters. different story if you have Anion resin in one canister and Cation in another.

They should be both packed tight. I'll have to look at it closer. I wonder what else could cause it?

 

[SliceGolfer]

I wonder what else could cause it?

Depends on what’s in and the order of your DI canisters. If you have a 3 stage DI canister setup with cation, anion, and mixed bed resins, you’re stating your anion resin is depleting faster than the others. This is true in my RODI as well.

Cation resin removes cations, anion resin removes anions. Cations are positively charged ions, such as ammonium, sodium, calcium, magnesium. Anions are negatively charged, such as chloride, bicarbonate, phosphate. So it’s likely your source water is rich in chloride, bicarbonate, or phosphate.

 

[Gordonm]

I'm trying to follow what your saying. I have not heard the terms cation and anion resin before. As far as I know my resin is a mixed bed. The order of my DI canisters is just two canisters one after the other of mixed bed. Does this make any sense to you?

 

[Gordonm]

Also does it not make sense that DI resin in my first canister would NOT be used because of it going into my last canister thereby using that DI resin?

 

[Randy Holmes-Farley Verified Community Expert]

FWIW, if you are not using mixed bed DI resins, TDS is NOT a suitable way to determine if it is working or if it is depleted. Those resins MUST have higher TDS in their effluent than the water coming into them, unless they are totally spent in which case it will be identical.