Hi Fabio,
To answer your question.
Yes. I have had hugh 50,000uF capacitors across a setup, years ago.
My answer will not help you with your schematic, but i can tell you the effects it had.
Listen very carefully, please.
You always searched for a highly efficient way of producing HHO.
With this massive capacitor, power wise, i had a very efficient solution.
Same gas output for less electricity.
I thought: yeah!!!
The negative effect was that my test-engine ran worse! Same amount of gas!
So, less brownsgas effects. Less isotopes...
Just the lowest energy molecule came out.
Hope this explains it all...