Don't worry about mold or fungus on the model/type I posted. The panel (that you replace annually) is treated with an anti-fungal and there really isn't any moisture that stays in that pad. The controller kicks the solenoid on when it calls for moisture, soaks the pad, and then turns off. The air moving across the pad dries the pad pretty much completely in between cycles. When I swap out my pad there is never any sign of anything but lime scale on it.