RO water quality question

[raptor72]

So I've finished putting together my RO/DI prep. area. My question is this: Does the container that the water collects in have to be air tight to maintain RO/DI quality?

 

[tangs rule]

No - in fact I like mine to be able to breath some in storage - so I just keep the lids covering, but cocked a little to allow some air exchange. I also mix the salt in the same cans - but only mix the salt a day or so in advance of a waterchange.....mixing salt earlier seems to allow ALOT of the minerlas in the mix to deposit on the plastic over time. I used to keep new saltwater premixed all the time, with a little powerhead running in it, but over a couple months, you'll get calcium and good mineral buildup in the can, lowering the value of "new" water. Once these deposits begin to settle out - the growth seems to accelerate. I've had the bottom 1/3 of my cans almost fully coated with calcium before, and it;s a pain to remove.