DI system only system questions

[Dburr1014]

The granular particles are to fine to separate

When you add sodium hydroxide the anion floats, and you tip it out into another jug. The cation stays in the first jug, as it doesn't float, thus;

This is exactly how it's done. The chemical will seperate them for you.

If you have separate resins and recharge, what benefit is there to ever mixing them and then making recharge impossible until you separate them again?

I always thought that a "mixed bed" is better to polish water. Correct me if I'm wrong.

 

[charleydavis]

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 don't understand the problem. If TDS is zero out of the anion stage you have great water. When did you last change the RO membrane? Eliminating the RO membrane is not a good idea. How good or bad is your soucre water? What does it contain?

 

[Dburr1014]

Source water is approximately 34 tds measured by inline tds meter and verified by a pen type tds meter.

I don't understand the problem. If TDS is zero out of the anion stage you have great water. When did you last change the RO membrane? Eliminating the RO membrane is not a good idea. How good or bad is your soucre water? What does it contain?

 

[Freenow54]

If you have separate resins and recharge, what benefit is there to ever mixing them and then making recharge impossible until you separate them again?

I did not mix them. I ordered it off of Amazon before I learned today that they came sepererate. Or I would have done it that way. ( see downloaded picture from earlier.
Did you get a chance to look at the diagram I downloaded for you yet?

 

[Freenow54]

If you want to use them fully then yes running them separate is needed, but you also need to run two in series so you can run the first one in line until it is fully changed color and the second is catching what gets past the first one before it's totally exhausted.

Which do you put first?

 

[Randy Holmes-Farley]

This is exactly how it's done. The chemical will seperate them for you.

I always thought that a "mixed bed" is better to polish water. Correct me if I'm wrong.

People may claim it, but I don’t see a reason to think that.

 

[Randy Holmes-Farley]

Which do you put first?

Order should not matter.

 

[Randy Holmes-Farley]

Did you get a chance to look at the diagram I downloaded for you yet?

Where?

 

[Freenow54]

Where?

Number 21

 

[Randy Holmes-Farley]

Number 21

Hard to see exactly, but it looks like an undercounter zero waste RO drinking water system. It carries the risks I mentioned, including bacterial contamination of drinking water, and I do not recommend it. I do not deny that some folks use them. Folks do all kinds of things I do not recommend, such as eating raw hamburger.

Zero Waste RO Systems: Revolutionary Solution or Clever Marketing?

Reverse Osmosis Water Waste: How Much Water Is Really Used? [Complete

Discover the truth about reverse osmosis water waste. Learn how RO systems work, their efficiency, and eco-friendly alternatives for clean drinking water.

premieresales.com

 

[Freenow54]

Hard to see exactly, but it looks like an undercounter zero waste RO drinking water system. It carries the risks I mentioned, including bacterial contamination of drinking water, and I do not recommend it. I do not deny that some folks use them. Folks do all kinds of things I do not recommend, such as eating raw hamburger.

Zero Waste RO Systems: Revolutionary Solution or Clever Marketing?

Reverse Osmosis Water Waste: How Much Water Is Really Used? [Complete

Discover the truth about reverse osmosis water waste. Learn how RO systems work, their efficiency, and eco-friendly alternatives for clean drinking water.

premieresales.com

Could you point out how cross contamination could happen? That is the watts system

 

[Syntax1235]

I don't understand the problem. If TDS is zero out of the anion stage you have great water. When did you last change the RO membrane? Eliminating the RO membrane is not a good idea. How good or bad is your soucre water? What does it contain?

The original post asked the question why the tds was higher after the cation stage, I received the answer and am satisfied.

 

[Randy Holmes-Farley]

Could you point out how cross contamination could happen? That is the watts system

Bacteria can and do grow between the carbon filter (that removes disinfectant chlorine and chloramine) and the ro membrane.

If that possible bacterial contamination gets reinjected into the hot water line, then someone may be washing their hands, washing their dishes, or even drinking it. For example, run the hot water in a kitchen sink, turn off the tap, and walk away. Some of that water is in the line between the handle and the faucet spout. Someone comes along later for a drink of cold water, turns on the cold to fill a glass, and out comes that first segment of now cooled, and possibly contaminated hot water.

This sort of cross connection can become extreme in some situations. In my college dorm, when too many people had both hot and cold taps on at the same time, water can leave the hot and enter the cold in some mixing valves, and our toilets flushed with hot water, and the cold water tap ran hot.

 

[Freenow54]

Hard to see exactly, but it looks like an undercounter zero waste RO drinking water system. It carries the risks I mentioned, including bacterial contamination of drinking water, and I do not recommend it. I do not deny that some folks use them. Folks do all kinds of things I do not recommend, such as eating raw hamburger.

Zero Waste RO Systems: Revolutionary Solution or Clever Marketing?

Reverse Osmosis Water Waste: How Much Water Is Really Used? [Complete

Discover the truth about reverse osmosis water waste. Learn how RO systems work, their efficiency, and eco-friendly alternatives for clean drinking water.

premieresales.com

All the water is treated straight from the cold. It goes through the sediment filter then the carbon then to the pump. I have no idea if the water can flow in reverse back through the pump . If it can then yes I can see contamination if there is a pressure drop in the town supply.There are differences with the way my system is piped if you will. I do not use an expansion tank that is used in conjunction with a drinking water faucet. Also not clearly marked is a check valve before it goes into the hot line and cannot backwash through the system. So I fail to understand the ex sales persons statement of " flushing the membrane " which cannot be done unless as I said the water can backlog through the pump. Sorry for the prejudice about the lady who wrote the article but the heating and cooling company I worked for is run by salespeople who mostly lie to people. She says that an old system is less efficient. How is that even possible when it is all canisters with cartridges we change? Anyway. So the final thing I failed to mention is the " tank " line continues to my DI filter then into my container. The other is pinched off so no flow or pressure build up. FInnally I have shut off valves on the cold outlet and the hot into the hot line and both are shut off when I am done and the booster pump is unplugged so it is isolated completely. So what should have been " waste " water in some systems due to what she called the flushing of the membrane does not take place. The water that goes back into the hot line is treated water in my case. As a point of interest which I wished I still had a picture of the sediment filter but it was on my computer that crashed turns from white to a completely disgusting black. Hope that makes sense to you let me know if you think I am missing something. It would not be the first time. I am trying to be as ecologically friendly as I can. I used to subscribe to a Canadain publication called harrowsmith. Back in the early 80s. I did what you would refer to as a thesis on a much smaller scale of course in one of my trades on solar which was in its infancy? Not very efficient but interesting to me. Still have a book on energy efficient homes.

 

[Freenow54]

The original post asked the question why the tds was higher after the cation stage, I received the answer and am satisfied.

Yes sorry for taking over but I thought you wanted to save water as well which is why I mentioned what I use

 

[Randy Holmes-Farley]

The original post asked the question why the tds was higher after the cation stage, I received the answer and am satisfied.

It is a good question that periodically arises. The pH is also greatly impacted.

The pH after an anion resin alone is very high, because it replaced all negatively charged ions with OH- (hydroxide). That is why TDs rises: OH- is a better conductor of electricity than any other anions by a large margin.

Likewise, after a cation resin alone, the pH is very low because the resin swapped out H+ for all the cations. TDS rises because H+ is by far the highest conductivity cation.

After both, the H+ and OH- combine, neutralizing the pH and dropping the TDS below 1 ppm.

 

[Randy Holmes-Farley]

All the water is treated straight from the cold. It goes through the sediment filter then the carbon then to the pump. I have no idea if the water can flow in reverse back through the pump . If it can then yes I can see contamination if there is a pressure drop in the town supply.There are differences with the way my system is piped if you will. I do not use an expansion tank that is used in conjunction with a drinking water faucet. Also not clearly marked is a check valve before it goes into the hot line and cannot backwash through the system. So I fail to understand the ex sales persons statement of " flushing the membrane " which cannot be done unless as I said the water can backlog through the pump. Sorry for the prejudice about the lady who wrote the article but the heating and cooling company I worked for is run by salespeople who mostly lie to people. She says that an old system is less efficient. How is that even possible when it is all canisters with cartridges we change? Anyway. So the final thing I failed to mention is the " tank " line continues to my DI filter then into my container. The other is pinched off so no flow or pressure build up. FInnally I have shut off valves on the cold outlet and the hot into the hot line and both are shut off when I am done and the booster pump is unplugged so it is isolated completely. So what should have been " waste " water in some systems due to what she called the flushing of the membrane does not take place. The water that goes back into the hot line is treated water in my case. As a point of interest which I wished I still had a picture of the sediment filter but it was on my computer that crashed turns from white to a completely disgusting black. Hope that makes sense to you let me know if you think I am missing something. It would not be the first time. I am trying to be as ecologically friendly as I can. I used to subscribe to a Canadain publication called harrowsmith. Back in the early 80s. I did what you would refer to as a thesis on a much smaller scale of course in one of my trades on solar which was in its infancy? Not very efficient but interesting to me. Still have a book on energy efficient homes.

There is no reversing the pump or anything else. It is the waste water itself that is contaminated, and forward pushing the waste water back into the hot water system is the issue.

If you sanitize the waste water before pushing it back in, that solves the bacterial contamination issue and is a big reduction in concern. So now you have to have a UV and a booster pump on the waste line, adding significantly to the expense.

 

[Freenow54]

Bacteria can and do grow between the carbon filter (that removes disinfectant chlorine and chloramine) and the ro membrane.

If that possible bacterial contamination gets reinjected into the hot water line, then someone may be washing their hands, washing their dishes, or even drinking it. For example, run the hot water in a kitchen sink, turn off the tap, and walk away. Some of that water is in the line between the handle and the faucet spout. Someone comes along later for a drink of cold water, turns on the cold to fill a glass, and out comes that first segment of now cooled, and possibly contaminated hot water.

This sort of cross connection can become extreme in some situations. In my college dorm, when too many people had both hot and cold taps on at the same time, water can leave the hot and enter the cold in some mixing valves, and our toilets flushed with hot water, and the cold water tap ran hot.

I did not realize that and can totally understand what you are saying. How does bacteria grow I don't understand that but not arguing. I can imagine many scenarios in that case. Luckily for me as I explained I do not use my system for drinking water so that wont happen. My last post states the only way it could happen in my case and involves it being used which it isnt when I am done making my water and a power outage and the town water supply loosing pressure all at the same timeAs to your mixing valve situation I spent hours trying to explain that to customers because their hot water was tempered down . They rarely believed you but if the plumbing was exposed I could prove it. Thank you for your time and patience

 

[Randy Holmes-Farley]

Between the carbon block and the RO membrane is a great place for bacteria to grow. No disinfectants, and plenty of nutrients in the tap water. The RO membrane mostly keeps bacteria out of the product effluent.

Hidden Dangers With Your Reverse Osmosis System

www.totalwaterllc.com

Recently we were at a customers house changing the filters in the Ro system. Their system was not producing much water and their membrane was not rejecting any TDS (total dissolved solids) which is the method of knowing whether or not your RO unit is producing purified water. Upon removing the canisters in which the sediment filter and pre-carbon filter were we found some serious slime build up. It was a gelatinous mass that had built up in the filters as well as within the RO manifold blocking the ability of the water to flow freely throughout the ports. The membrane had also been contaminated with this gelatinous mass. What was the gelatinous mass? Bacteria.

 

[KStatefan]

I did not realize that and can totally understand what you are saying. How does bacteria grow I don't understand that but not arguing. I can imagine many scenarios in that case. Luckily for me as I explained I do not use my system for drinking water so that wont happen. My last post states the only way it could happen in my case and involves it being used which it isnt when I am done making my water and a power outage and the town water supply loosing pressure all at the same timeAs to your mixing valve situation I spent hours trying to explain that to customers because their hot water was tempered down . They rarely believed you but if the plumbing was exposed I could prove it. Thank you for your time and patience

That is why it is recommend to sanitize a drinking water RO system every 6 months of so.