7 ms·

I trust my municipality to give me microbiologically safe water. Because I trust bleach, not my local water authority. I certainly do not trust them to give m

I trust my municipality to give me microbiologically safe water. Because I trust bleach, not my local water authority. I certainly do not trust them to give me chemically clean water. So I have a $150 under-sink RO system.

bilsbie 1y ago
Is there a chance it can get contaminated with bacteria? I worry about the water sitting in there.
- Xss3 1y ago
  A properly working RO system will prevent viruses and bacteria from passing. For the extra paranoid you can get systems with a UV sterilisation step.
  - Xss3 1y ago
    Just to add, most municipalities chlorinate the water slightly, so its highly unlikely youll find anything alive in it. My water is fairly heavily chlorinated where i live compared to my previous county. Letting the glass of water sit in open for a few minutes after pouring helps with taste because the chlorine evaporates.
    - vel0city 1y ago
      If you have a lot of chlorine taste just having a pitcher in the fridge will nearly eliminate the chlorine taste.
- mousethatroared 1y ago
  I've thought about this, but I don't think so. My last two paragraphs addresses what I think are RO's risks. First there has to be bacteria in the municipal water. The city does a pretty good job there, Second there has to be organic matter for the bacteria to grow. Again, cities are good with that. But even if you have bacteria in your water, a good RO system's pores should be smaller than a virus (really smaller than a prion) or it won't be able to remove metallic ions. But let's assume after two years these assumptions fail because the filters get old. Replace the filters and flush the system with bleach. My fear with RO are bad filters. I once had a Zero pitcher and it tasted bad, acidic. A few weeks later there was a recall that the RO membrane was leaking ionomers. Moral of the story- trust your senses. If municipal water tastes bad, it's bad. If bottled water tastes bad, it's bad. If RO water tastes bad, it's bad.
  - malfist 1y ago
    From someone that keeps aquariums, municipal water that is stripped of it's chlorine by carbon has the ingredients to grow bacteria. They need three things, carbon, phosphate and nitrogen, all of which will be present to varying degrees. Particularly nitrates and phosphates. They're not harmful until concentrations are really high but certainly enough to grow bacteria. Also consider what your holding tank and supply to the water, either through leaching, accumulation or simply time
    - mousethatroared 1y ago
      Now strip it with an RO filter.
      - malfist 1y ago
        RO (without DI) does not remove everything. With an advanced setup like with a booster pump and a 5:1 waste ratio and a high quality filter you would probably see a 95% reduction. But without a booster pump or if you've got a lower waste ratio either by restriction or piggyback ro membranes you'll have a lower rejection rate. And that ignores the fact the you really need to be back flushing the membrane regularly and rejection rates are measured after 30 minutes of continuous running, ions migrate when it's idle so you have to throw away a lot of water at the start that you're probably not doing
rurban 1y ago
Only third world problems. In advanced societies we don't care about unsafe water because we can drink tap water. (Sure, the US is third world)

bilsbie 1y ago

Is there a chance it can get contaminated with bacteria? I worry about the water sitting in there.

Xss3 1y ago
A properly working RO system will prevent viruses and bacteria from passing. For the extra paranoid you can get systems with a UV sterilisation step.
- Xss3 1y ago
  Just to add, most municipalities chlorinate the water slightly, so its highly unlikely youll find anything alive in it. My water is fairly heavily chlorinated where i live compared to my previous county. Letting the glass of water sit in open for a few minutes after pouring helps with taste because the chlorine evaporates.
  - vel0city 1y ago
    If you have a lot of chlorine taste just having a pitcher in the fridge will nearly eliminate the chlorine taste.
mousethatroared 1y ago
I've thought about this, but I don't think so. My last two paragraphs addresses what I think are RO's risks. First there has to be bacteria in the municipal water. The city does a pretty good job there, Second there has to be organic matter for the bacteria to grow. Again, cities are good with that. But even if you have bacteria in your water, a good RO system's pores should be smaller than a virus (really smaller than a prion) or it won't be able to remove metallic ions. But let's assume after two years these assumptions fail because the filters get old. Replace the filters and flush the system with bleach. My fear with RO are bad filters. I once had a Zero pitcher and it tasted bad, acidic. A few weeks later there was a recall that the RO membrane was leaking ionomers. Moral of the story- trust your senses. If municipal water tastes bad, it's bad. If bottled water tastes bad, it's bad. If RO water tastes bad, it's bad.
- malfist 1y ago
  From someone that keeps aquariums, municipal water that is stripped of it's chlorine by carbon has the ingredients to grow bacteria. They need three things, carbon, phosphate and nitrogen, all of which will be present to varying degrees. Particularly nitrates and phosphates. They're not harmful until concentrations are really high but certainly enough to grow bacteria. Also consider what your holding tank and supply to the water, either through leaching, accumulation or simply time
  - mousethatroared 1y ago
    Now strip it with an RO filter.
    - malfist 1y ago
      RO (without DI) does not remove everything. With an advanced setup like with a booster pump and a 5:1 waste ratio and a high quality filter you would probably see a 95% reduction. But without a booster pump or if you've got a lower waste ratio either by restriction or piggyback ro membranes you'll have a lower rejection rate. And that ignores the fact the you really need to be back flushing the membrane regularly and rejection rates are measured after 30 minutes of continuous running, ions migrate when it's idle so you have to throw away a lot of water at the start that you're probably not doing

rurban 1y ago

Only third world problems. In advanced societies we don't care about unsafe water because we can drink tap water. (Sure, the US is third world)