R/O systems need to backflush and it takes some fairly decent water pressure to push the water through the filters - in either direction.

Go to the plumbing department at Lowe's or HomeDePot, tell them what you want to do and they'll sell you a valve that is easy enough to install and then you can hook the sytem up the right way.

...or you could dick around with pumps and stuff, but, why bother? It's easier to install it the right way, and it's even easier to uninstall it if you have to move.

PC :smokin: