hi.
I am surprised that anyone who admit they drink DIed water after what I said, Louey, you naive, uninformed (and rich) reefer! :wink:
In most RO/DI setup with output for both drinking water and DI for tank, there is a storage tank that stores the RO. When you want drinking water, the storage tank will push the RO thru a post filter, and into your glass/cup. If you want water for your tank, the storage tank will push the RO thru the DI canister(s) to your tank.
There is no need to wait 20 minutes for a glass of water. See OEM web or reef hardware store (e.g., marinedepot.com, spectrapure.com, etc.) for a pic of "drinking water kit" setup.