We used a clear plastic hose available at any hardware store along with two couplers. Again, drill the hole the size of the hose. Push the hose through both barrels, and attach the couplers on the inside. We used some 20 gauge steel wire to make sure the couplers didn’t pop off (they keep the hose from coming out of the barrel). Use the pliers to twist the wire as tight as possible around the hose where the coupler connects. Lastly use silicon around the hole to make it water tight.