This is way over my head but it's cool seeing someone experimenting. That's how you further a hobby.
It should be pretty simple once i work everything out. It reads co2 to control the solenoid to the co2 tank instead of the guessing game of bubbles per second, timer, or ph meters.
I really do hope this gizmo will wipe out killing your fish and the dreaded BBa. No more co2 swings. That was the primary motivation for working on this.