If you have an older Jet system that was installed with an aerator timer we do not suggest altering the time settings. If you feel you need to make an adjustment, contact your Jet service provider and they will diagnose your system to see if timer adjustments are warranted. Currently all new Jet systems are installed with continuous run aerators, the wear on the motor windings and bearing life due to condensation that occurs when cycling motors far outweighs the small cost savings in power usage when operating the aerator on a timer.