Have to be gone for extended time. Need to have some device to fill rez if it get low for the last few days I will be away. What would be the best way??? Thought of a second rez with pump and some sort of limiter switch that would tell the water level in the rez and if it got low turn on the pump in the second rez to refill it? Please Help as I will be losing a big crop... Thanks....kiss-ass