The water detecter can detect water and help you decide whether your plants need watering or perhaps to see if it is raining outside.

Parts needed:
                    some insulated wire
                    a light of some sough that works
                    battery (9V)

Construction details:
                              Hook the battery up to the light as in the diagram below but make a gap to put some wire in. These wires are you probes, put the probes into the thing you want tested and if the light turns on it has water in it.

How it works:
                     Water conducts electricity so the broken circuit work when the probes are in water and the light turns on.
 

Diagram of the water tester.