5 ms·

I was instructed (from professional chemists) to NOT drink 1 MOhm ( or other highly-purified) RO water. At that purity, particularly when hot, it will leach me

I was instructed (from professional chemists) to NOT drink 1 MOhm ( or other highly-purified) RO water. At that purity, particularly when hot, it will leach metals and other compounds from pipes, pots, cups, etc. Maybe it's worth dropping a little salt into the water after purification? I'm also surprised that you use the waste water on your aquarium. In my experience, fish are MUCH more sensitive to water quality than humans are. This is particularly true for corals in saltwater tanks. In fact, many aquarium stores sell RO-purified water for fish tanks!

sevenless 10y ago
I do not see why extremely pure water would leach metals any more than tapwater would. Chemically it should not matter. All species will reach equilibrium between the surface of the container and the liquid and if dilute they will not care about one another. That equilibrium will be reached faster if the temperature is higher. What is true is that you should not drink hot water from pipes because hot water does leach metals, tapwater or otherwise.
- michaelcampbell 10y ago
  Was this not the issue in Flint, Michigan with the water leaching lead because it DIDN'T have something in it?
  - vessenes 10y ago
    No, the water there was more acidic than the prior water the system used, causing leaching.
    - michaelcampbell 10y ago
      I see; thanks.
- ridgeguy 10y ago
  Very pure water is corrosive. I built a CVD lab that had aluminum deposition chambers plumbed into a DI water cooling system. The water was fed from a purifier that provided 18MΩ-cm water. The water corroded the aluminum chamber cooling passages, leaving aluminum hydroxide behind. This conversion of metallic aluminum to a gelatinous, clogging hydroxide was what alerted us to the problem. Feed pressure (regulated) was fine, but flow rates fell and chambers heated up. We had to wire brush all cooling channels, a total pain. We ran on tap water for a couple of weeks while we researched the issue, and had very little corrosion but had other issues (mineral deposits). Finally, we reverted to 18MΩ water and added ~10% volume of ethylene glycol (antifreeze, basically). Once we "degraded" the water purity with glycol, our corrosion problems stopped. It was very counterintuitive. Here's an industry source that has a little bit to say about the corrosive properties of pure water: http://www.lytron.com/Tools-and-Technical-Reference/Application-Notes/Deionized-Water http://www.lytron.com/Tools-and-Technical-Reference/Applicat.... Given the industrial importance of the problem, I'm sure there are in-depth chemistry explanations. Haven't pursued them.
spyder 10y ago
Drinking just RO water isn't the healthiest thing because the RO removes the useful minerals too, and that's why there are add-ons to most RO systems for re-mineralization. http://www.survivopedia.com/how-to-re-mineralize-water/ http://www.survivopedia.com/how-to-re-mineralize-water/ http://www.waterbenefitshealth.com/reverse-osmosis-water.html http://www.waterbenefitshealth.com/reverse-osmosis-water.htm...
- dingleberry 10y ago
  just eat plenty of vegetables and fruits. they contain minerals and more palatable.
  - zymhan 10y ago
    No, the point is we never normally drink totally pure water, we nearly always drink mineral water. Mineral water does in fact taste better most of the time. Pure H20 is going to start dissolving all sorts of stuff from it's surrounding, making it taste odd.
  - deleted 10y ago
    [deleted]
goldenkey 10y ago
They are right. 1 MOhm water will jack the minerals off your teeth. OP would be lucky to not have cavities forming right this second.
- dingleberry 10y ago
  i do have cavities on back of my lower jaws; however, it's not due to RO water. should RO water is causing this, the damage distribution should be uniform -> my other teeth should be equally damaged. i still have other teeth intact, no holes, despite using ro water for 8 years or so. i think there's the cause of my holes. i had wisdom teeth very late in age. my brushing pattern wasn't sufficient. moreover, i was addicted to oatmeal power drink and didn't brush after. those sugary flakes seem to linger on my back jaws. yudkin book, "pure, white and deadly" discusses this. children who drink sugary vs eating candies. same sugar; however, those eating candies get more cavities simply because candies stick between teeth ... think twinkies on interesting part of the book is about the slave in sugar plantations. they did eat raw sugar; however, the slaves didn't get the same disastrous level of disease as the masters, who eat refined sugar.
  - goldenkey 10y ago
    Cavity damage isn't uniform though. It depends on location of exposure and the way the mouth salivates. It makes sense that the cavities are toward the back of the tongue. Anyhow, I would be careful. Just get a potassium chloride rock and throw it in the water. No biggie.
- Panoramix 10y ago
  How could that be the case? Tap water is nowhere close to mineral saturation. It should make an astronomically small difference. If anything, it could be less corrosive due to the higher resistance. I do see a possibility for it to be slightly more corrosive in pipes under specific circumstances, due to the lack of anything forming a passivating layer on the long run. But for teeth I have a hard time believing this.
  - goldenkey 10y ago
dingleberry 10y ago
i used to store hot water in thermos that the inside glass got stain from hard water (apartment water was hard, contains a lot of mineral) after i got a son, we replaced hard water with ro water, including the thermos. well, baby is important, right? over time (months), the stains are gone, the glass inside the thermos got cleaner. so yeah, ro water being soft water probably cancels out the stains from hard water previously used. on waste water for aquarium: it's because you misrepresent 'waste water'. water in an ro unit gets filtered four times (must go thru 4 different filters). the first is sediment, and the last is the ro membrane. can't remember the middles. the sediment filter gets brown over time and need to be replaced (cheap, ~$1 per cylinder). so there's some impurities captured. after last filter, the membrane, the water that fails to pass becomes 'waste water'. it's actually clear, tasteless, just didn't pass the ro membrane. so ro waste water is actually cleaner than the input water. my fishes are okay with water from well. naturally, they should be okay too with water that's cleaner than well water. on heavy metal, fishes are very sensitive to cu, not so much for pb. so if fishes are healthy and not jittery or die after a day, the water should be okay. i also bought ro unit for my soft-water fishes: neon tetra. accidently, i found that human can drink ro water too ;)
jrapdx3 10y ago
It's not a theoretical issue, and not limited to RO water supplies. Here in Portland Oregon the municipal water source is Bull Run Watershed high up in the foothills of Mt. Hood, some 26 miles east of downtown. The collected water is basically similar to distilled water since it's formed directly from cloud/fog condensate. Consequently the default pH is ~6.8-7.0, which leaches lead from old plumbing. The federal government forced the city to add sodium hydroxide to increase the pH to ~8.0 and reduce corrosion. Obviously city water has very little dissolved solids which in principle could have health implications re: Ca, Mg intake. Diet is normally the main source of these minerals, not clear how much additional risk is attributable to low mineral content of household water. Most people here consider our water to be very palatable as is and are reluctant to have further modifiers applied to it. If any new federal requirements are attempted it's likely to elicit a lot of controversy and pushback.

sevenless 10y ago

I do not see why extremely pure water would leach metals any more than tapwater would. Chemically it should not matter. All species will reach equilibrium between the surface of the container and the liquid and if dilute they will not care about one another. That equilibrium will be reached faster if the temperature is higher. What is true is that you should not drink hot water from pipes because hot water does leach metals, tapwater or otherwise.

michaelcampbell 10y ago
Was this not the issue in Flint, Michigan with the water leaching lead because it DIDN'T have something in it?
- vessenes 10y ago
  No, the water there was more acidic than the prior water the system used, causing leaching.
  - michaelcampbell 10y ago
    I see; thanks.
ridgeguy 10y ago
Very pure water is corrosive. I built a CVD lab that had aluminum deposition chambers plumbed into a DI water cooling system. The water was fed from a purifier that provided 18MΩ-cm water. The water corroded the aluminum chamber cooling passages, leaving aluminum hydroxide behind. This conversion of metallic aluminum to a gelatinous, clogging hydroxide was what alerted us to the problem. Feed pressure (regulated) was fine, but flow rates fell and chambers heated up. We had to wire brush all cooling channels, a total pain. We ran on tap water for a couple of weeks while we researched the issue, and had very little corrosion but had other issues (mineral deposits). Finally, we reverted to 18MΩ water and added ~10% volume of ethylene glycol (antifreeze, basically). Once we "degraded" the water purity with glycol, our corrosion problems stopped. It was very counterintuitive. Here's an industry source that has a little bit to say about the corrosive properties of pure water: http://www.lytron.com/Tools-and-Technical-Reference/Application-Notes/Deionized-Water http://www.lytron.com/Tools-and-Technical-Reference/Applicat.... Given the industrial importance of the problem, I'm sure there are in-depth chemistry explanations. Haven't pursued them.

spyder 10y ago

Drinking just RO water isn't the healthiest thing because the RO removes the useful minerals too, and that's why there are add-ons to most RO systems for re-mineralization. http://www.survivopedia.com/how-to-re-mineralize-water/ http://www.survivopedia.com/how-to-re-mineralize-water/ http://www.waterbenefitshealth.com/reverse-osmosis-water.html http://www.waterbenefitshealth.com/reverse-osmosis-water.htm...

dingleberry 10y ago
just eat plenty of vegetables and fruits. they contain minerals and more palatable.
- zymhan 10y ago
  No, the point is we never normally drink totally pure water, we nearly always drink mineral water. Mineral water does in fact taste better most of the time. Pure H20 is going to start dissolving all sorts of stuff from it's surrounding, making it taste odd.
- deleted 10y ago
  [deleted]

goldenkey 10y ago

They are right. 1 MOhm water will jack the minerals off your teeth. OP would be lucky to not have cavities forming right this second.

dingleberry 10y ago
i do have cavities on back of my lower jaws; however, it's not due to RO water. should RO water is causing this, the damage distribution should be uniform -> my other teeth should be equally damaged. i still have other teeth intact, no holes, despite using ro water for 8 years or so. i think there's the cause of my holes. i had wisdom teeth very late in age. my brushing pattern wasn't sufficient. moreover, i was addicted to oatmeal power drink and didn't brush after. those sugary flakes seem to linger on my back jaws. yudkin book, "pure, white and deadly" discusses this. children who drink sugary vs eating candies. same sugar; however, those eating candies get more cavities simply because candies stick between teeth ... think twinkies on interesting part of the book is about the slave in sugar plantations. they did eat raw sugar; however, the slaves didn't get the same disastrous level of disease as the masters, who eat refined sugar.
- goldenkey 10y ago
  Cavity damage isn't uniform though. It depends on location of exposure and the way the mouth salivates. It makes sense that the cavities are toward the back of the tongue. Anyhow, I would be careful. Just get a potassium chloride rock and throw it in the water. No biggie.
Panoramix 10y ago
How could that be the case? Tap water is nowhere close to mineral saturation. It should make an astronomically small difference. If anything, it could be less corrosive due to the higher resistance. I do see a possibility for it to be slightly more corrosive in pipes under specific circumstances, due to the lack of anything forming a passivating layer on the long run. But for teeth I have a hard time believing this.
- goldenkey 10y ago

dingleberry 10y ago

i used to store hot water in thermos that the inside glass got stain from hard water (apartment water was hard, contains a lot of mineral) after i got a son, we replaced hard water with ro water, including the thermos. well, baby is important, right? over time (months), the stains are gone, the glass inside the thermos got cleaner. so yeah, ro water being soft water probably cancels out the stains from hard water previously used. on waste water for aquarium: it's because you misrepresent 'waste water'. water in an ro unit gets filtered four times (must go thru 4 different filters). the first is sediment, and the last is the ro membrane. can't remember the middles. the sediment filter gets brown over time and need to be replaced (cheap, ~$1 per cylinder). so there's some impurities captured. after last filter, the membrane, the water that fails to pass becomes 'waste water'. it's actually clear, tasteless, just didn't pass the ro membrane. so ro waste water is actually cleaner than the input water. my fishes are okay with water from well. naturally, they should be okay too with water that's cleaner than well water. on heavy metal, fishes are very sensitive to cu, not so much for pb. so if fishes are healthy and not jittery or die after a day, the water should be okay. i also bought ro unit for my soft-water fishes: neon tetra. accidently, i found that human can drink ro water too ;)

jrapdx3 10y ago

It's not a theoretical issue, and not limited to RO water supplies. Here in Portland Oregon the municipal water source is Bull Run Watershed high up in the foothills of Mt. Hood, some 26 miles east of downtown. The collected water is basically similar to distilled water since it's formed directly from cloud/fog condensate. Consequently the default pH is ~6.8-7.0, which leaches lead from old plumbing. The federal government forced the city to add sodium hydroxide to increase the pH to ~8.0 and reduce corrosion. Obviously city water has very little dissolved solids which in principle could have health implications re: Ca, Mg intake. Diet is normally the main source of these minerals, not clear how much additional risk is attributable to low mineral content of household water. Most people here consider our water to be very palatable as is and are reluctant to have further modifiers applied to it. If any new federal requirements are attempted it's likely to elicit a lot of controversy and pushback.