According to {TAIL ~ a feature} of the invention, {HEAD ~ the tank} has a number of water outlets spaced along the lower water collection region and controlled by valves which may be programmed to open periodically and sequentially 
According to { TAIL ~ a feature } of the invention , { HEAD ~ the tank } has a number of water outlets spaced along the lower water collection region and controlled by valves which may be programmed to open periodically and sequentially
REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH