The thing about rodi, is it doesn't taste very good.
We are used to a certain amount of non h2o in our water and we miss it when it's not there. So they wouldn't make a lot of money selling pure water for drinking. They do sell pure water, it's labeled as "distilled" even though the fine print usually says "distilled by ro di." People use distilled water for things that have to be pure like steam irons that would get clogged from residue, and baby formula.
Different brands of "drinking water" will have their own mix of non-h2o that they either leave I when they take the water from a spring, or municipal supply of the city they contract with for a source; or that they add back after purifying the water. Without knowing what that stuff is, I wouldn't use "drinking water" in my tank. Especially when you can buy distilled water from Walmart for $1 a gallon. IMO buying that and adding salt is the best option. Lots of happy smaller tanks run this way.
Whichever type of water you buy, I'd double check the tds of each jug and treat it with a conditioner like Prime in case they use copper pipes or fittings at the bottling plant. Just to be on the safe side.
