How have you wound the coils?

try to measure the voltage across the chokes without a cap and see if it varies when you change frequency (don't now if this is valid, but you can try it, need a hv probe). if it does, try to find the highest voltage by adjusting the frequency.

Try the same with the cap.

meyer said Xl > Xc, which means the impedance of the choke is max (no current, max voltage) and the impedance of the watercap is minimal (all current through cap) @ a frequency = no current trough coil and all current through cap (but amps are choked), try to look for these properties.

Just fool around

you know what to look for, try not to get obsessed with trial and error to get bubbles, that is a step ahead, look for no current, max voltage and step charging by finding out the correct dutycycle (T2 < T1), T2 equals the timeconstant of the choke.