R/O Water Storage Question

[Myka]

What kind of buckets are these? I'm assuming they are old salt buckets, but maybe they aren't? I use a couple of food safe 65 gallon barrels for my water, and even after a month the water still has 0ppm TDS. I don't even use lids on them, just drape towels over them to keep dust out. I over-think everything too, and I'm super anal about things like RO/DI water, so in my case I would find your current situation unacceptable for fear of what exactly is that 5-10ppm anyway?? For the average reefer, probably not an issue.

[spawn]

They're food grade pails bought new from a plastics store here in the city. Not old salt pails. It was unacceptable to me as well that's why I didn't use it. However I don't like wasting all the water. So if the few ppm come after the 0tds water goes from my res into the mixing pails, it has to be some kind of residual from my mixing & obviously not perfect cleaning. So I'm not going to worry about it anymore, as long as the water coming out of the R/O Di. reads 000TDS.

[Phoenix_M]

Hi all,

new here, but saw this and thought i'd give you some insight.
you're probably experiencing carbon dioxide dissolving in the water. yup it does. this also alters the pH of the water very slightly too.
carbon dioxide and pH are closely linked; and works similarly to your blood. it's a 'buffer' system, and as pH changes, so does the amount of dissolved carbon dioxide, etc. it's in a balance. in your blood, actually, the change clicks your heart/lungs to race faster when there's higher c02 dissoloved.

essentially if you want to knwo more, look into the buffer equation for carbonate buffer systems. something like:

H2C03 <--> HC03(-) + H(+) <--> C03(2-) + 2H(+)
notice the left side has NO H+, the right side has 2 of them (the more "H+" you have, the higher the pH

there's your science.

-m