In my experience, the original chinese scheme working not very well. The pressure is growing constantly. I made some changes based on the Russian forums recommendations, and I added some my own improvement. Now, I have a very stable system, pressure is totally consystent (started from 1.5ATM, may floating around, depend of a temperature or so, between 1.3 - 1.7, it's pretty enough).
The proper proportions are:
acid: 150g+200ml of water
soda: 200g+minimal amount of water enough to cover a soda.
You can load more, just keep a proportion.
My last load (acid: 300g+400ml of water, soda 400g + minimal amount of water to cover soda) still working for my 75G tank with a dropchecker control 24/7 more of 3 weeks for now.
The scheme is attached.
It is very important to put the acid output at the bottom of the soda bottle, under the soda layer, instead to drop it from the top.
Also, using a needles is important for acid dosage. You will need at least one needle at the soda's side of the system; I prefer to use two with some reasons. You can try.
You will be unable to starting the system in common way; anyway it was too annoying for me. I using the car air pump to make a proper pressure in the system. Bicycle air pump should be OK, too
It is much faster and easiest, at least for me
P.S. Also, I played with a ceramic diffusers, and they are just a garbage. I received a really small bubbles (like a gas dust) only with a twig; I using maple twig but you can try some other woods. Works just perfect and cost nothing.