Is It Ok To Store Ro Water?

[jarmado]

i am planning to try out RO water from my lfs.
is it ok to store RO water for a long time?
i will be buying more than i need to save me some trip to the lfs.

thanks in advance.

 

[Liam]

I can’t think of any reason not to store it. If it’s stored in food safe containers, so that no plastics end up in the water and nothing else gets into it would remain the same as the day you get it.

 

[jarmado]

I can’t think of any reason not to store it. If it’s stored in food safe containers, so that no plastics end up in the water and nothing else gets into it would remain the same as the day you get it.

thanks for the advice.
i was so tempted to buy cheap ones from ebay but is now worried that it may leak stuff on the water.
il'll get the proper water containers.

 

[jarmado]

i have read from one of TFF thread that storing RO water will greatly raise the ph.
is this true?

 

[CFC]

Theres no reason that the pH would rise in pure R/O water stored in a suitable and sealed container. Just remember to heavily aerate the water with a airstone after a long period of sitting to re oxygenate it before adding it to the tank.

 

[jarmado]

Theres no reason that the pH would rise in pure R/O water stored in a suitable and sealed container. Just remember to heavily aerate the water with a airstone after a long period of sitting to re oxygenate it before adding it to the tank.

do i need to aerate the stored RO even if i will be mixing it with treated tapwater before adding it to the tank?
thanks.


post#3 on this thread mentioned about the raise in pH (just to show that i read it from here:
http/www.fishforums.net/index.php?showto...79&hl=tds+meter

 

[a.d.wood]

Hi there,

Aerate your water prior to use, when I was using drums, this would be for 24 hours.

I wouldn't trust the pH reading from pure RO water, because of (and apologies for the little bit of chemistry):

Distilled/deionised/RO water has a very low ionic strength. There is no pH value on the basis that all of the ions have been removed if the process has been effective. Therefore a pH meter/test strip is effectively trying to measure something that does not exist, and minute changes in the dissolved gases (such as dissolved CO2) can give large variations in the readings obtained (to get a reliable reading, saturated potassium chloride can be added to increase the ionic strength, but of course you don't want this to end up in the aquarium).

Andrew

 

[Majjie]

I thought that the pH of RO or any other "pure" water would decrease on storage because of absorption of CO2 from the air - forming carbonic acid.

It would only become alkaline if there were other basic salts present (if you'd already added re-mineralising salts, for instance).

I would store your RO water without adding anything to it and keep the container as full as possible. If it is then acidic it will only be weakly so and mixing it with tap water - if that's what you're going to do - would easily neutralise that acidity. Aerating the water might also help to drive off dissolved CO2 as well as adding O2.

 

[jarmado]

Hi there,

Aerate your water prior to use, when I was using drums, this would be for 24 hours.

I wouldn't trust the pH reading from pure RO water, because of (and apologies for the little bit of chemistry):

Distilled/deionised/RO water has a very low ionic strength. There is no pH value on the basis that all of the ions have been removed if the process has been effective. Therefore a pH meter/test strip is effectively trying to measure something that does not exist, and minute changes in the dissolved gases (such as dissolved CO2) can give large variations in the readings obtained (to get a reliable reading, saturated potassium chloride can be added to increase the ionic strength, but of course you don't want this to end up in the aquarium).

Andrew

I thought that the pH of RO or any other "pure" water would decrease on storage because of absorption of CO2 from the air - forming carbonic acid.

It would only become alkaline if there were other basic salts present (if you'd already added re-mineralising salts, for instance).

I would store your RO water without adding anything to it and keep the container as full as possible. If it is then acidic it will only be weakly so and mixing it with tap water - if that's what you're going to do - would easily neutralise that acidity. Aerating the water might also help to drive off dissolved CO2 as well as adding O2.

thanks!