As Antonin Fourneau's Water Light Graffiti will be presented in Poitiers during the the Prise de la Bastille, he's decided to experiment with some animated fountain effects. A simple, quick and cheap solution was to find an electric squirt gun. We found a basic model in a local bazaar that shoots up to 4 meters! Since the propulsion of the water is controlled by a DC motor, this means we can change the force by introducing a programmed microcontroller (Arduino). Adding a microphone and employing an open source FFT library available for the arduino environment the water gun can be activated stronger or softer according to different frequencies. The idea is to introduce an amplified anthem at a given moment during the day of festivities to control multiple water guns. Voila, a makeshift sound activated water fountain, a.k.a. a hackers' delight :)