DI system only system questions

[Syntax1235]

Hello,

I've been using RO/DI for years; however, I've decided to try and reduce water usage by eliminating the RO membrane stage. My system is as follows:

Source water is approximately 34 tds measured by inline tds meter and verified by a pen type tds meter. I also have in-line tds meters after the second carbon block and after each di stage.

1) sediment filter
2) 5-micron carbon block
3) 1-micron carbon block (tds out of the second block is 44) - maybe there is still residue from the carbon blocks as this shouldn't be higher than the source water?
4) cation single resin di block (tds out of this stage is 107)
5) anion single resin di block (0 tds out of this stage)

I don't understand how the tds is so high out of the cation di resin stage.? I just changed out my carbon blocks and flushed them for 20 minutes before hooking up the di stage. The di resin is only a few months old and doesn't show any color change... I'm using the BRS single bed resins.

I'm wondering if anyone can help me understand why the tds is high out of the cation stage.

I'm going to use this system for a while to see how fast I go through the resin. If all goes well, I will add another di stage and be able to eliminate waste water from my water-making process.

Thank you for any insight.

 

[Timfish]

I do not know, however, as I understand, TDS meters are using a voltage to determine TDS. So I'd guess either either your filters are increasing TDS somehow or altering the conductivity somehow to let the meter read a higher number.

 

[Dburr1014]

Hello,

I've been using RO/DI for years; however, I've decided to try and reduce water usage by eliminating the RO membrane stage. My system is as follows:

Source water is approximately 34 tds measured by inline tds meter and verified by a pen type tds meter. I also have in-line tds meters after the second carbon block and after each di stage.

1) sediment filter
2) 5-micron carbon block
3) 1-micron carbon block (tds out of the second block is 44) - maybe there is still residue from the carbon blocks as this shouldn't be higher than the source water?
4) cation single resin di block (tds out of this stage is 107)
5) anion single resin di block (0 tds out of this stage)

I don't understand how the tds is so high out of the cation di resin stage.? I just changed out my carbon blocks and flushed them for 20 minutes before hooking up the di stage. The di resin is only a few months old and doesn't show any color change... I'm using the BRS single bed resins.

I'm wondering if anyone can help me understand why the tds is high out of the cation stage.

I'm going to use this system for a while to see how fast I go through the resin. If all goes well, I will add another di stage and be able to eliminate waste water from my water-making process.

Thank you for any insight.

Something in my head is telling me this is normal, like I read it somewhere.

@Buckeye Hydro you are a rodi guy, maybe you can answer.

 

[Syntax1235]

I should have researched this more thoroughly. I have a post by Randy that explained the raise in TDS... for anyone interested, here's his response to a similar question:

DI Cation Resin Low in / high out

Purchased new BRS resin for my 3 stage DI's. The Cation (#1) is adding 2TDs to the water. 1 in 3 out. This is something new. It did not do this on the last batch. Anyone else have this happen?

www.reef2reef.com

Randy's post:

"A cation binding releases one or two H+ (Rarely 3) for every cation bound. H+ is by far the most conductive ion, so TDS rises and the pH drops.
The anion resin releases one or two OH- (rarely 3) for every anion bound. Hydroxide also conduct very well so the TDS and pH rise.

Then when those fluids combine, the H + and OH- combine exactly to make nonconductive H2O."

 

[Randy Holmes-Farley]

Yes, one type of DI resin will greatly boost TDS, then the other type eliminates it.

Also, TDS out of carbon block can also rise as some neutral (nonconductive) molecules such as chloramine are broken apart into conductive ions (chloride and ammonia in this case).

You are calling the DI stages 'blocks". Why? Are they literally a block, or do you mean an ordinary DI cannister?

 

[Syntax1235]

You are calling the DI stages 'blocks". Why? Are they literally a block, or do you mean an ordinary DI cannister?

Yes, I meant canister. It seems like my water does not consume cation nearly as fast as the anion; fortunately, recharging the anion seems like a fairly simple process.

 

[Dburr1014]

Yes, I meant canister. It seems like my water does not consume cation nearly as fast as the anion; fortunately, recharging the anion seems like a fairly simple process.

Anion use could be co2 in the water.

 

[redfishbluefish]

If you're just using the 10 inch canisters, you're going to go through resin pretty fast.

I don't know if it's still around, but years ago....maybe 15 years or so....there was a system called Kati Ani that simplified regeneration of the respective resins. Came with larger canisters and if I remember correctly, three different sizes. A friend had this system and could make about 75-80 gallons before he had to regenerate.

You would regenerate right in the canisters.

 

[Shirak]

Yes, I meant canister. It seems like my water does not consume cation nearly as fast as the anion; fortunately, recharging the anion seems like a fairly simple process.

This is pretty typical. I need to change anion every 6 months or so. Cation every few years and the canister is half the size.

 

[Freenow54]

Hello,

I've been using RO/DI for years; however, I've decided to try and reduce water usage by eliminating the RO membrane stage. My system is as follows:

Source water is approximately 34 tds measured by inline tds meter and verified by a pen type tds meter. I also have in-line tds meters after the second carbon block and after each di stage.

1) sediment filter
2) 5-micron carbon block
3) 1-micron carbon block (tds out of the second block is 44) - maybe there is still residue from the carbon blocks as this shouldn't be higher than the source water?
4) cation single resin di block (tds out of this stage is 107)
5) anion single resin di block (0 tds out of this stage)

I don't understand how the tds is so high out of the cation di resin stage.? I just changed out my carbon blocks and flushed them for 20 minutes before hooking up the di stage. The di resin is only a few months old and doesn't show any color change... I'm using the BRS single bed resins.

I'm wondering if anyone can help me understand why the tds is high out of the cation stage.

I'm going to use this system for a while to see how fast I go through the resin. If all goes well, I will add another di stage and be able to eliminate waste water from my water-making process.

Thank you for any insight.

I have been trashed for suggesting this just lately like as if Its open season to criticize without input and assuming you the recipient cant think for themselves so look up a zero waste system made by watts in Arizona. As to your dilemma I can only suggest what I use this resin is off amazon and It lasts forever. Two precautions maybe you did not know. You cannot let it dry out or expose to light. I have done about 7 changes and still have about 2?3 left I keep it in a 3 inch ABS pipe with a cap on one end and a screw top on the other

 

[Freenow54]

Hello,

I've been using RO/DI for years; however, I've decided to try and reduce water usage by eliminating the RO membrane stage. My system is as follows:

Source water is approximately 34 tds measured by inline tds meter and verified by a pen type tds meter. I also have in-line tds meters after the second carbon block and after each di stage.

1) sediment filter
2) 5-micron carbon block
3) 1-micron carbon block (tds out of the second block is 44) - maybe there is still residue from the carbon blocks as this shouldn't be higher than the source water?
4) cation single resin di block (tds out of this stage is 107)
5) anion single resin di block (0 tds out of this stage)

I don't understand how the tds is so high out of the cation di resin stage.? I just changed out my carbon blocks and flushed them for 20 minutes before hooking up the di stage. The di resin is only a few months old and doesn't show any color change... I'm using the BRS single bed resins.

I'm wondering if anyone can help me understand why the tds is high out of the cation stage.

I'm going to use this system for a while to see how fast I go through the resin. If all goes well, I will add another di stage and be able to eliminate waste water from my water-making process.

Thank you for any insight.

Well I just got trashed for days about the fact that Watts in Arizona makes a zero waste RO system. I guess no one thinks thae person I am taliking to has a functional mind. Anyway some had no suggestions of there own just wanted to harp on me. I am not defending a manufacturers product even if they have been around for decades. So Look it up and decide for youself. As to DI resin and your problem I cannot comment exept to show you the resin I use from amazon. I have about 2/3 of the package left which I kweep in a DIY container of 3 inch ABS with an adapted scre

w top. Maybe that is the issue? You are not supposed to let it dry out or expose to light. Anyway have done about 7 resin changes at least.

I have been trashed for suggesting this just lately like as if Its open season to criticize without input and assuming you the recipient cant think for themselves so look up a zero waste system made by watts in Arizona. As to your dilemma I can only suggest what I use this resin is off amazon and It lasts forever. Two precautions maybe you did not know. You cannot let it dry out or expose to light. I have done about 7 changes and still have about 2?3 left I keep it in a 3 inch ABS pipe with a cap on one end and a screw top on the other

Try This maybe

 

[Randy Holmes-Farley]

Yes, I meant canister. It seems like my water does not consume cation nearly as fast as the anion; fortunately, recharging the anion seems like a fairly simple process.

That’s common with CO2 in the water, which is often the case with well water.

 

[Randy Holmes-Farley]

I have been trashed for suggesting this just lately like as if Its open season to criticize without input and assuming you the recipient cant think for themselves so look up a zero waste system made by watts in Arizona. As to your dilemma I can only suggest what I use this resin is off amazon and It lasts forever. Two precautions maybe you did not know. You cannot let it dry out or expose to light. I have done about 7 changes and still have about 2?3 left I keep it in a 3 inch ABS pipe with a cap on one end and a screw top on the other

You were not trashed for suggesting di only, which you did not do. I criticized the suggestion to send waste water back into the potable water system using a booster pump diy.

DI only can be fine, but expensive.

 

[Syntax1235]

That’s common with CO2 in the water, which is often the case with well water.

I'm using tap water that seems very clean at 34-36 tds. I'm keeping careful track of how long the di resin lasts, I'm hopeful it is worth the extra cost but time will tell. I can easily replumb the ro membranes back into the system if this doesn't work out.

 

[Syntax1235]

This is pretty typical. I need to change anion every 6 months or so. Cation every few years and the canister is half the size.

I'm curious as to how much water you are making weekly and if you are using only sediment/carbon/di system? Also your tds level out of your tap?

I'm making around 40 gallons a week for mixing and top-off.

 

[Shirak]

I'm curious as to how much water you are making weekly and if you are using only sediment/carbon/di system? Also your tds level out of your tap?

I'm making around 40 gallons a week for mixing and top-off.

Currently making about 50-60 gallons a week. I use it for my espresso machine, watering plants etc so not just the tank setup.

I am on a well. Water is usually between 260-300ppm TDS depending on how much rain we have had. Post RO it will drop to 4ppm TDS pretty quickly and after 5 or 10 minutes drop to 2ppm with my 99% reduction membrane.

The source water is hard, Ca heavy due to the limestone rock the water comes through. It's cold at 55 degrees F. and silty so the whole house is filtered down to 1micron. From there a 1/2" pex feeds the RO housing. (4" x 24" high flow RO membrane in SS housing). RO output gets a carbon block post filter before DI. There is a valve and line to pull RO pre-DI. From there DI splits in parallel and goes through two ROBuddie filters packed with cation media. Recombines and goes to the anion where there are two sets of two BRS canisters. Recombines again and goes through a single ROBuddie packed with mixed bed media.

I don't use a booster pump or preheat the water so depending on how new the house filters are it could take 15min or up to 45min to fill a 5g bucket. I run a pretty high pressure on my well pump but I also run quite a bit of waste water to help keep the membrane clean due to the potential for silt to clog it. The waste water just goes out the the septic system on the other side of the house..

Any other questions let me know.

 

[Syntax1235]

Currently making about 50-60 gallons a week. I use it for my espresso machine, watering plants etc so not just the tank setup.

I am on a well. Water is usually between 260-300ppm TDS depending on how much rain we have had. Post RO it will drop to 4ppm TDS pretty quickly and after 5 or 10 minutes drop to 2ppm with my 99% reduction membrane.

The source water is hard, Ca heavy due to the limestone rock the water comes through. It's cold at 55 degrees F. and silty so the whole house is filtered down to 1micron. From there a 1/2" pex feeds the RO housing. (4" x 24" high flow RO membrane in SS housing). RO output gets a carbon block post filter before DI. There is a valve and line to pull RO pre-DI. From there DI splits in parallel and goes through two ROBuddie filters packed with cation media. Recombines and goes to the anion where there are two sets of two BRS canisters. Recombines again and goes through a single ROBuddie packed with mixed bed media.

I don't use a booster pump or preheat the water so depending on how new the house filters are it could take 15min or up to 45min to fill a 5g bucket. I run a pretty high pressure on my well pump but I also run quite a bit of waste water to help keep the membrane clean due to the potential for silt to clog it. The waste water just goes out the the septic system on the other side of the house..

Any other questions let me know.

Gotcha. I thought you were using di only, the ro explains the di resin longevity.

 

[Shirak]

Gotcha. I thought you were using di only, the ro explains the di resin longevity.

Sorry for the confusion! I think even if you are going DI only the cation will last considerably longer than the anion, so you will need bigger anion housings and a good system to DIY renew it.

 

[Freenow54]

That’s common with CO2 in the water, which is often the case with well water.

How do you recharge the anion? Also it sounds like you buy it and house it separate from one to the other is that correct?

 

[Garf]

How do you recharge the anion? Also it sounds like you buy it and house it separate from one to the other is that correct?

Sodium hydroxide generally