I have a unique setup that includes a fishtank, so I dont have to account for run-off, but mine is on a forced system from the tank pump that rises to the top of the cage to a tube that forms an oval inside the ceiling of the cage. In this tube I have added 7 1/2 GPH drippers that, when active, "rain" inside the cage. I have moved some of the vines and leaves inside the cage to maximize the spread of the water, allowing multiple places for Gron to drink from.