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Spotless Water

Slightly OT but is it ok to let this water stand for a long time? Just thinking that a 25l container would last quite a few months

I think that any water that is left to stand for a period of time will eventually start going through a nitrogen cycle so its a good way to test for ammonia and nitrite before re-using if long enough period has passed from filling the container. I'd also trust the tap water quality control more than some "water supply" place. These days even bottled drinking water has been found to be contaminated.
 
Slightly OT but is it ok to let this water stand for a long time? Just thinking that a 25l container would last quite a few months

It should fine if you store it in a black container or in the dark, I use to have a large container that always full of RO near a window, after my weekly water change I use to fill it back up. I was slightly surpised as it built up a layer of diatom algae , then started to go slightly green.

I guess the filter wasn't as good as I thought.
 
Hi all,
I think that any water that is left to stand for a period of time will eventually start going through a nitrogen cycle
RO won't, it doesn't have any nutrients so will just stay the same, potentially for all of eternity. It will absorb gases until it equilibriates with atmospheric levels, but that is it.
I use to have a large container that always full of RO near a window, after my weekly water change I use to fill it back up. I was slightly surpised as it built up a layer of diatom algae , then started to go slightly green. I guess the filter wasn't as good as I thought.
Yes <"growth of algae"> is a good indication that your RO unit need servicing.

We used <"to get it with the distillation units">, but we don't get it with the <"Elga Veolia DI units"> we use now.

cheers Darrel
 
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Hi all,RO won't, it doesn't have any nutrients so will just stay the same, potentially for all of eternity. It will absorb gases until it equilibriates with atmospheric levels, but that is it.Yes <"growth of algae"> is a good indication that your RO unit need servicing.

We used <"to get it with the distillation units">, but we don't get it with the <"Elga Veolia DI units"> we use now.

cheers Darrel

Reminds me of a documentary I saw about those pure water underwater caves in Africa - the same water from 10,000 years ago and blind albino catfish as inhabitants (among many others). It's the clearest water I've ever seen.
 
Things about RO water and RO water generation.....

1. An RO unit IS NOT guaranteed to produce 100% RO water, even if all membranes, pre-filters and DI resins are 100% tip-top, which is why you should always test RO before use. Testing using a TDS pen is fine, better is ammonia and/or free chlorine testing.
2. Home RO generation wastes water, typically 4:1, if lucky, waste water to RO water. ie 4 litres waste to 1 litre RO. Most will be 10:1 - 6:1 waste to RO. The higher the incoming water pressure the less waste produced, use of booster pumps improves efficiency.
3. Commercial RO generation uses much much higher pressure on the membranes and can achieve 90% or more efficiency, as well as recovering a large % of the energy put in in pressurising the water.
4. For tap water, a pre-filter must be used remove chlorine as chlorine will attack the membrane. If chloramine is present in your tap water a specialist pre-filter must be used.
5. If flow rate is too high, the pre-filter may not be able to remove all the chlorine and chlorine will find its way into the RO water output. (and damage membrane).
6. If flow rate is too high or incorrect pre-filter used with chloramine in tap water, the chloramine will get broken down to chlorine and ammonia and not be filtered out. The ammonia will find its way into the RO water output. (and damage membrane).
7. RO water should be stored in sealed opaque container. RO water will absorb carbon dioxide from the air and as water is such a good solvent will dissolve out chemicals from the storage container and provided enough nutrients for algae & bacteria to grow. RO should really be used as soon as made.
 
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