If you had a water capacitor charged there is a point where the voltage potential is zero, exactly in the middle of the capacitor. If it were floating ground or isolated ground during charging.
If you connect one of the leads of a charged capacitor to ground?
Basically nothing because the net charge is zero, the only think is that you are going to relocate the zero potential.
Ex you connect the negative side of a capacitor charged to 40kv while isolated, to ground. what happens?
Well as the negative side is more negative than ground electrons should go to ground? If this could happen you would end up with charge imbalance on the capacitor? I guess the answer to that is to think in this way since a capacitor work based on bound link charges the above statement is impossible since the polarization of the dielectric holds the electrons or the capacitor would get discharged!
This ability allow the choice of an arbitrary ground in whatever circuit and still calculate the potentials unaffectedly.
Stan repeatedly talks about water having zero charge because it has zero charge but is not neutral under all conditions.
If you apply a greater E field than the one that holds those ions together they will split apart and now you have a zone of net positive charges and another with negative charges. (still net zero)
Now if you neutralize this second field but allow some electrons to burn off from the circuit during this discharge than its clear the water will take up a positive charge probably going out in gas form...