DIY CO2 -- A VERY simple reactor

[peterinwa]

I read that you can make a very simple reactor with a plastic up upside down so that the bubbles rise up into it.

My question is why it said the cup should be clear so that you could see how many bubbles were being produced. I'd think it would fill up with air (CO2) and then just stay full?

So maybe they meant that you could start with it empty or empty it whenever you wanted and then see how fast it filled. That makes sense and is probably what they meant.

I'm posting just to be sure that's right. Please tell me if this simple reactor should have a little hole in it or some method of releasing the air. I'm assuming not, that it just holds it and the water below the air pocket extracts the CO2.

And as new bubbles come in old bubbles get pushed out. ???

[Glud]

The meaning of that kind of reactor is that the CO2 will be caught in the cup, and slowly diffuse into the water. Of course when the cup gets full some of the CO2 will be pushed out.

[m.lemay]

When you first put the cup in, makes ure there is no air in it. The co2 will fill it and the water flowing under the cup will absorb the co2. This method works for a small tank. You can speed up the process by running a current with a powerhead under the cup so that the water/gas exchange takes place quicker. This methid probably won't work very well for anything larger than a 15 gal tank. You do not put a hole in the cup. The idea is to trap the gas long enough so that it'll get dissolved into the water.

[peterinwa]