Water runs into the SWS-200 solar still in a slow continuous stream. During the day, much of this source water evaporates and is distilled, but there is always some excess that exits the still. At night, when there is no evaporation, the flow rate of this excess increases. Typically, about 1/2-1 gallon of water is lost at night. Excess water is typically directed to a tree (ideally a mulch basin).
If you wish to save a little water, though, you can manually turn off the faucet when the sun goes down, and turn it back on in the morning. This daily task may become tedious, and therefore Do-Right Solar offers an irrigation timer that screws on to the faucet, and can be set to turn on/off the flow of water automatically. The watering period can be set anywhere between 1 minute and 23 hours 59 minutes.