| The Hydor Koralia Photo-Electric Cell plugs into the Hydor Wavemaker and is used to slow down the circulation pumps controlled by the Wavemaker during the night hours. When the aquarium lighting system turns off the Photo-Electric Cell senses the reduction in light and signals the Wavemaker to slow the pumps down to minimum power. When the light turns back on the pumps will return automatically to the set program. | 
