For electronic circuit has two transistors wired as a pair, together with high gain.
2N2222A transistor T1 and T2 is BC108.
The actual profit will be the proceeds of any beta-transistors with a minimum of 140 x 110 or 15,400.
Power supply is a voltage from 4.5 to 15 volts, a kind of relay 5 Volt at 60 mA is required to in this case, any liquid with a stream of at least 4 others to the relay. It is easy to reach with tap water or rain.