While degradation of output is accelerated if the lamp is switched on and off more than once per hour, the lamps are suitable to be used for 'ON/OFF' applications such as evacuating septic tanks, and weekend holiday home use where the system is turned off when the home is vacated. For ON/OFF applications we advise wiring the power supply to the UV system, then to a 2 minute timer, then to the pump. This allows time for the lamp to heat up to operating temperature before water flows.