Poll: Preferred DI Setup

[saltyhog]

I run a dual canister mixed bed setup and move the #2 canister to the #1 slot when I need to repack #1. (does that make sense?).

I'm fortunate in that the tap water in my community is of excellent quality with a usual TDS of about 35. Most of the time the TDS is 0 after going through my sediment filter/carbon blocks/RO membrane. At most it's 1-2. My DI resin lasts a long time.

 

[Gareth elliott]

Use the 4 stage brs with a single mixed bed.
Honestly it was my budget that decided this. My towns water uses chlorine not chloramine, and low organics. I currently get 0 tds, not sure on longevity its only been up this current year.

 

[MnFish1]

anion and cation are what make up DI resin. Cation has a positive charge and Anion has a negative charge. It's most commonly used in a mixed bed (the blue resin) to attract different negatively and positively charged ions in your water. What has been happening lately is instead of running a mixed bed, people are running two cartridges, one with Anion and one with Cation to give the water more contact time with each resin, and then a mixed bed at the end to fully polish it off

Curious - What is the reason for this? - if a single mixed bed works well. Seems its just more media to change and more complicated. Is there some evidence that having 3 mixed bed canisters (for example) as compared to 1 anion, 1 cation and 1 mixed bed is any better (or worse)? It seems like there is still the same amount of each type of media in both of these examples.

 

[d2mini]

I buy my pre-made cartridges from SpectraPure. They really know their stuff. Way more than I do!

 

[dbl]

I buy my pre-made cartridges from SpectraPure. They really know their stuff. Way more than I do!

+1 Dennis...same thing here.

 

[KMench]

Curious - What is the reason for this? - if a single mixed bed works well. Seems its just more media to change and more complicated. Is there some evidence that having 3 mixed bed canisters (for example) as compared to 1 anion, 1 cation and 1 mixed bed is any better (or worse)? It seems like there is still the same amount of each type of media in both of these examples.

I think it just helps remove any hard to get stuff like silicates which can make it through. Also, they mix mixed resin 50/50 and we actually burn through the anion (I think it’s this one) faster than the cation. So if you separate the two, you can only replace the one resin that is depleted faster instead of wasting part of the other resin that isn’t depleted, but still in the mixture.

 

[MnFish1]

I think it just helps remove any hard to get stuff like silicates which can make it through. Also, they mix mixed resin 50/50 and we actually burn through the anion (I think it’s this one) faster than the cation. So if you separate the two, you can only replace the one resin that is depleted faster instead of wasting part of the other resin that isn’t depleted, but still in the mixture.

Thanks. But - if you use 1 anion, 1 cation and 1 mixed - its the same as using 3 mixed. But - if you're saying there is a color change that allows you to make that decision - that makes good sense. Is there? Im only asking because the RODI I have has the usual 'filter' at the start the carbon second and the resin last - so it would be an investment to change it up...

 

[KMench]

I would assume there is color changing single bed resin. I don’t have it, and run only one single mixed bed. Unless you’re having problems burning through resin, or still have silicates or another problem ion left in your rodi water, I personally don’t feel the need for it.

 

[redfishbluefish]

My choice of "What I prefer" isn't there. My preference is a dual single bed system with one canister having cation resin and the other anion resin.

I regenerate the resin, with the first step having to separate the two resins from a mixed resin. To simplify this first step, I attempted to set up the two canister system with individual resins. This would make regeneration very simple. I know this kind of thing works from the old Cati-Ani systems that use to be sold. Having an old two canister bracket, I gave it a try:

Now here's the weird thing....it didn't work. I'd still get the 2 TDS coming out of this system. I scratched my head on this one and to make sure I had good individual resins, I mixed the two together, and now I was getting the expected 0 TDS. This puzzled me to no end, so I tried again, and the same result. So now I run a single mixed bed canister, but I'd prefer this two canister system.

 

[siggy]

I used this back in the Y2K era, My LFS had this and were I got my water, He still uses it.( He never checks it with tds meter) probably why My tank had algae then .....So now I use a PRE + 2 carbon + 2 DI mixed bed & no RO membrane, I get about 75-90 gallons about 5 water changes and top off water. I am going threw 5 gallons 3-4 days top-off so maybe 4 WC plus TO. This route I can get 20 gallons in 15 minutes & WC and maintenance done in 40 BTW this popped up for sale, he said that its good for 300 gallons

 

[Water Dog]

I buy my pre-made cartridges from SpectraPure. They really know their stuff. Way more than I do!

+1 Dennis...same thing here.

Exactly what I do as well.

 

[skim]

I have twin mixed bead for know but I think I will try the BRS triple when I need to change out my present resign. I don't really think you would need the three.

 

[cracker]

just for clarification. I assume that a "mixed" resin contains both.
Also which one or something else takes care of silicates?
i just e/med my water co, & asked about silicate levels. They already told me they don't use cloramines.

 

[lancesmith1]

I use the BRS packages, someone let me know what that is and i will vote.

 

[KMench]

I use the BRS packages, someone let me know what that is and i will vote.

Brs premix should be a mixed bed resin.

 

[Adele]

I think @Adele meant they had 8-9 tds going into their DI after coming out of their ro membrane
Edit: I may or may not have misunderstood the question

Yep. 8-9 going in. Always 0 coming out.

 

[Adele]

Have you ever thought of using a container to degas and remove the CO2?

Yes. But still mulling over the hassle of adding the extra container and pump to send it back to the resin after degassing. Probably isn’t as difficult as I think it would be and might be easier than hooking up two more resin cartridges.

 

[Gareth elliott]

just for clarification. I assume that a "mixed" resin contains both.
Also which one or something else takes care of silicates?
i just e/med my water co, & asked about silicate levels. They already told me they don't use cloramines.

Silica can exist in both charged form and uncharged in water. Charged can be removed by anion resin. The uncharged colloidal form is removed by the ro membrane. I dont honestly know which is more common in water supplies.

 

[MTBake]

Here's some pics of setup. I use three stages. I have high silicate in my tap water. Cation, anion, anion mixed bed from brs. Really like it so far. Looks like I need to stock up anion resin

 

[SteadyC]

Curious - What is the reason for this? - if a single mixed bed works well. Seems its just more media to change and more complicated. Is there some evidence that having 3 mixed bed canisters (for example) as compared to 1 anion, 1 cation and 1 mixed bed is any better (or worse)? It seems like there is still the same amount of each type of media in both of these examples.

Watch this, very good explanation of why it’s more effective and uses less resin at the same time. Quick spoiler alert, in a mixed bed resin, the ation depletes faster and you are throwing away some portion of cation that isn’t fully depleted. They get into,it pretty quick but starting at 1:30 they discuss the cost savings.
https://www.bulkreefsupply.com/vide...ates-mixed-or-single-bed-di-resin-maybe-both/