I make my ro water just before I brew. It goes straight into my HLT (3v system) like Bobby says. The system itself hangs on the side of my brew cart, but could easily sit on a shelf or on the wall. I run an rv hose to the system from the outside faucet when I'm ready to use it. Have a bucket lid with a float which sit on the keggle to shut it off, in case I forget what I'm doing.