valve 87 which is toggled between an open and a closed position by a plunger 88 the plunger 88 is in turn toggled between the open and closed positions by a latching solenoid 90 fig7 which is operated by momentary u201c open u201d and u201c close u201d signals from a microprocessor 92 thus the controller 80 consumes significant power only momentarily while switching from one valve state to the other the controller 80 is powered by a battery 94 because a battery failure while the valve 87 is open could be catastrophic a battery power sensor 96 is provided in the controller 80 when battery power drops below a predetermined safe level the sensor 96 causes the cycle timer 98 in microprocessor 92 to close the valve 87 and lock itself in the u201c off u201d mode until the battery 94 is replaced the microprocessor 92 includes four operational elements an hours counter 100 the cycle timer 98 a valve actuator 104 and an led control 106 the counter 100 cyclically counts off twenty four one hour intervals and then issues a start signal 108 to the cycle timer 98 the cycle timer 98 preferably includes a day counter and five selectable timing routines off no.