(Science Buffs) How do you dissolve gas in water?

[kerrywins]

Example...how do you dissolve CO2 in water?
thank you in advance to the really smart person who answers this.

[soothsayer]

1. don'tcha' just bubble it into the water, and some gets in there?

I'd better check that answer....


ok, from this site http://www.thekrib.com/Plants/CO2/ (with pics!):

Reactors

Once you have chosen your CO2 source, you must get it to dissolve into the aquarium water.


The easiest, if not the most esthetically pleasing, method is to trap the gas in an upturned cup or ``bell''. While trapped, the gas eventually diffuses into the water


Another simple approach is to run the CO2 line into the intake of a powerhead of canister filter. The impeller helps break up and dissolve the bubbles.


You can build a gas reactor, which forces the CO2 to quickly mix with rapidly moving water in a small chamber. I (EO) wrote an illustrated article with construction details. So have other people.


Relatively new on the scene are ceramic/glass diffusers, available from ADA or Eheim. This method replaces both the reactor and metering valve entirely; The diffuser passes pressurized gas as tiny bubbles through the glass. There have been debates over a possible end-of-tank dump effect if you are not also using a good needle valve to regulate flow.

Finally, here are some more diffuser and reactor postings for more info. Nadeem Faiz drew up a nice illustrated diagram showing a full yeast generator, bubble counter, and bell diffuser. Incidentally, you might want to look at what kind of hose and valves you use to transport the CO2 to the tank. Cheap rubber check valves are known to disintegrate quickly from the carbonic acid!

[Surf Cowboy]

2. Fart in the bathtub.

[redqueen]

3. I suggest you just PM Professor GAC directly. n/t

[Lisa]

4. it helps if the water is cooled

Water can hold more gaseous compounds in general, if the temperature is low. (Kind of the opposite of heating up water to dissolve solids such as salt and sugar.)

Can you get dry ice (solid CO2) anywhere? If you are trying to saturate the water with CO2, this might be a quick-and-dirty way of doing it -- throw in a chunk of dry ice.

p.s. what the earlier poster said about little bubbles (and I'm sure Don Ho would agree!) -- anything that will increase the surface area exposed to the CO2 will help. I imagine that slow bubbling over time would also be good, for the same reason.