Purified Water vs. Distilled Water

[ted464]

I usually use distilled water for brewing and build it up with my additions/salts, but the store was out of distilled water. Instead I bought purified water which says that it went through a RO system. My question is, is this water the same as distilled and free of minerals? Should my additions be the same for the recipe I am making (Shakespeare Stout clone)?

 

[jekeane]

work with the assumption it is relatively the same. RO water uses a membrane to filter as a membrane ages more stuff gets into the water. If you don't use a TDS meter to measure the RO water you will never really know but for you situation i would operate under the idea that it is the same which it pretty much is if the membrane is in good shape.