OK to drink DI water?

[DFW]

Mr. Holmes-Farley, is there any reason that we should not drink water from our RO/DI filtration units? Thank you!

 

[Randy Holmes-Farley]

Yes, there is a small reason, IMO, but it is not what you think.

There's no concern from drinking DI water itself, unless it is the only thing you drink all the time.

Even then, comments that people make suggesting you'll be deficient in minerals are unfounded. No one says the same about drinking tap or bottled water that is very low in useful minerals. There are plenty of minerals in foods.

But, my possible concern is that the water no longer has any protection from bacteria after the water passes through the RO membrane, and post RO water is known to have bacteria in it (not from the source water, but growing on the membrane and downstream surfaces). Consequently, while the risk may be quite low, my concern is microbial contamination, just as it would be from drinking any water that you left sitting in a container for a substantial period before drinking it. If you are going to drink stored RO/DI water, you might want it treated with a UV or some other way of sanitizing it. But again, the risk is likely quite low.

 

[143MPCo]

Agreeably, most would say no, I do however have it plumbed into my kitchen sink (drinking faucet) and do use it for coffee and cooking...

 

[Randy Holmes-Farley]

As a follow up to my own comment, I have a vacation home that my family uses only once in a while. Any time we arrive, I flush out the cold water pipes before we drink anything from it, even though it was sanitized municipal water going in because once the chlorine and/or chloramine is gone bacteria can grow in it. So the concern is the same and not specific to DI water.

 

[Squishie89]

I talked to my veterinarian and she said it is fine for my birds, in fact she would prefer it over tap due to the high rate of giardia in our area. I don't think my birds are big fans of it, but they still drink it because they are not stupid. The birds and us get our minerals from our food mostly so really it is not as big a deal as some people make it out to be.

 

[mikellini]

Is that why my DI water smells after storage in the brute can for more than a day or two? I've been a bit concerned about using it for top off, but haven't had any problems so far. But I feel like I need to rinse and dry the can every couple of months. Even still, the smell comes back so it would make sense if the bacteria were growing in the filter. However I didn't think this to be likely, since bacteria need food I thought the filter and container would be close to sterile

 

[Cory]

My wife and I have talked about this too. I didn't know about the bacteria but it makes sense.

One concern I had is it's too pure and pure water can be aggressive to bodily tissues stripping it of minerals?

 

[AZDesertRat]

Legitimate RO vendors recommend disinfecting the RO or RO/DI system at least annually but I have found the few minutes it takes is worth your time at the 6 month filter replacement intervals. I say legitimate because there are literally thousands of vendors who assemble imported components and pass themselves off as RO experts when all they are doing is making a quick buck, no different than any other product or service that becomes popular.

During my Municipal water system supervision and operations days I was a witness to people being sick from drinking water from an RO syetm that had not been properly maintained. Several of those residents required brief hospitalization and a doctors care. I would usually sample from the RO faucet then from the outside hose bib closest to where the wate rentered their premises and every time the city water came back coliform bacteria free and the RO with high bacteria counts. In most instances they were rental properties or someone who bought a used home with an existing RO and did not know it needed maintenance.

While I recommend RO for drinking, as Randy said there can be dangers. You can reduce the chances by following recommended maintenance practices though and it only takes about 5 extra minutes during filter replacements.

 

[Squishie89]

Legitimate RO vendors recommend disinfecting the RO or RO/DI system at least annually but I have found the few minutes it takes is worth your time at the 6 month filter replacement intervals. I say legitimate because there are literally thousands of vendors who assemble imported components and pass themselves off as RO experts when all they are doing is making a quick buck, no different than any other product or service that becomes popular.

During my Municipal water system supervision and operations days I was a witness to people being sick from drinking water from an RO syetm that had not been properly maintained. Several of those residents required brief hospitalization and a doctors care. I would usually sample from the RO faucet then from the outside hose bib closest to where the wate rentered their premises and every time the city water came back coliform bacteria free and the RO with high bacteria counts. In most instances they were rental properties or someone who bought a used home with an existing RO and did not know it needed maintenance.

While I recommend RO for drinking, as Randy said there can be dangers. You can reduce the chances by following recommended maintenance practices though and it only takes about 5 extra minutes during filter replacements.

I was about to ask if this was okay to do for sanitizing the machine, and then realized you wrote it !! Cleaning/Sanitizing RODI Unit - Equipment Forum - Nano-Reef.com Forums Too funny

 

[Randy Holmes-Farley]

Is that why my DI water smells after storage in the brute can for more than a day or two? I've been a bit concerned about using it for top off, but haven't had any problems so far. But I feel like I need to rinse and dry the can every couple of months. Even still, the smell comes back so it would make sense if the bacteria were growing in the filter. However I didn't think this to be likely, since bacteria need food I thought the filter and container would be close to sterile

Quite a few people get that (I don't). My expectation is that it is mildew that grows on the Brute sides above the water, but I'm not sure.

 

[mikellini]

Anything to worry about when using this for top off or salt mixing?

 

[DFW]

Thanks Randy, and all for your comments here!

How many drops of bleach in a gallon of ro di water would sanitize it properly for drinking, just in case there are harmful bacteria?

 

[Randy Holmes-Farley]

Anything to worry about when using this for top off or salt mixing?

You mean because of bacteria? No.

 

[Randy Holmes-Farley]

Thanks Randy, and all for your comments here!

How many drops of bleach in a gallon of ro di water would sanitize it properly for drinking, just in case there are harmful bacteria?

You're welcome.

I'm not sure what method exactly is preferred to disinfecting the unit itself.

It won't be pleasant to drink the water using bleach to disinfect the water, but here's what the EPA suggests for bad water:

Emergency Disinfection of Drinking Water | Emergency Preparedness | US EPA

1. If you can't boil water, you can disinfect it using household bleach. Bleach will kill some, but not all, types of disease-causing organisms that may be in the water. If the water is cloudy, filter it through clean cloths or allow it to settle, and draw off the clear water for disinfection. Add 1⁄8 teaspoon (or 8 drops) of regular, unscented, liquid household bleach for each gallon of water, stir it well and let it stand for 30 minutes before you use it. Store disinfected water in clean containers with covers.

 

[Rob Top1]

I have two systems. RO/DI for my fish and lizard room and a RO unit for ice and drinking water.
In the FLR I store water in two 65gal polypropylene vats. Would you reccomend sterilization of those?
For the ice and drinking water it has a pressurized tank. Clean that too?

 

[mikellini]

You mean because of bacteria? No.

I was also thinking about the mildew you mentioned. Should I be worried about that? I'm thinking that it probably means the water is at least no longer 0 tds, but it still don't understand how things grow (especially to that extent) in a 0 tds environment...

 

[Randy Holmes-Farley]

I was also thinking about the mildew you mentioned. Should I be worried about that? I'm thinking that it probably means the water is at least no longer 0 tds, but it still don't understand how things grow (especially to that extent) in a 0 tds environment...

TDS isn't bad in the water. Seawater has a TDS of about 35,000 ppm. It all depends on what it is that the TDS consists of.

That said, I think the mildew (if that is what is causing the odor) is growing on the can above the water, and if that is the case, I wouldn't worry about it except as perhaps your own personal health issue (mold issues and such).

 

[Randy Holmes-Farley]

I have two systems. RO/DI for my fish and lizard room and a RO unit for ice and drinking water.
In the FLR I store water in two 65gal polypropylene vats. Would you reccomend sterilization of those?
For the ice and drinking water it has a pressurized tank. Clean that too?

I'd be more comfortable with a system that was occasionally sanitized, but how to do it isn't something that I have a procedure for.

 

[AZDesertRat]

I depressurize my 5G drinking water RO pressure tank, bleed out the air charge the disinfect it along with the system annually.

 

[eranschau]

Fascinating conversation. Sounds like the potential of bacteria grown in stored RO/DI isn't a concern for top off or salt mixing for aquarium use, but I do use my for making coffee and in the cat's water bowl (I have super hard water and the RO doesn't cause either the coffee maker or water bowl to crust up.) may not the the best idea..?