Being an Evil Mad Scientist in training, I always closely monitor the activities of the folks over at evilmadscientist.com. When I saw this article about carbonating small fruit recently it got me thinking:
The "standard" way of diffusing CO2 into liquid (for soda, etc.) is high pressure & low temperature. The low temp isn't really doable with an aquarium, but the CO2 is already at 900 psi or so. The trick would be getting the water to that pressure and then back to atmospheric.
Now, I know this is over the top complicated and current diffusers and reactors are probably plenty efficient, but I subscribe to the theory that anything that is worth doing is worth over-doing, so on with the gendankenexperiment
I am envisioning a pressure vessel with a water input valve, CO2 input valve and two water output valves, one restricted and one unrestricted. A controller opens the unrestricted water in and out valves to flush CO2 depleted water into the chamber. After a suitable flush period, all water valves are closed and the CO2 valve is opened, bringing the pressure in the chamber up to the full pressure of the CO2 canister. Again a suitable time is allowed to pass while the CO2 diffuses into the water. Then the CO2 valve is closed and the restricted water outlet valve is opened, allowing the chamber to return to low pressure without a fish-killing water-hammer shock. Then cycle begins again and the CO2 enhanced water is flushed into the tank.
Dangerous? Of course! (Don't try this at home kids!)
Will I build one? Probably not.
But hey, sharing crazy ideas is fun. And you never know, maybe someone will read this and it will spark an idea that is actually workable.