Since I have dehumidifiers operating in my humid Philadelphia, PA basement during warmer months (a typical thing here anyway), I figure why not use the water somehow? I hacked a dehumidifier I keep near a bathroom to pump water into the toilet during a flush. One AND gate chip checks that the toilet is flushing (water level drops) and dehumidifier has water before activating a fountain pump via 5V/120V relay to fill the toilet. The toilet tap water valve is turned down so that more dehumidifier water is used.

The toilet is fitted with a PVC pipe that sits on top of the toilet float. When the float is down during flushing, the pipe is down to activate a magnetic reed switch, letting the AND gate and indicator LED know the toilet is flushing.

When the dehumidifier has sufficient water so the pump doesn't run dry, a float rises to activate a magnetic reed switch that tells the AND gate and indicator LED the dehumidifier has water.