lets say that water vibrates at 1000 hz, then to produce resonance apply pulses of 1000 hz
the problem is that then the water will start vibrating at 999 hz and you are applying 1000 hz pulses so theres no resonance any more
the solution is simple, make a circuit that varies the phrequency of pulses in given and choseable increments so it will always keep up with the water phrequency untill it lowers so much the phrequency that the water splits
do you have any idea of how could be made a circuit that varies phrequency in given increments?