Originally Posted by Pappy Where can I get more info on CO2 powder?

Dry ice is solid CO2 that is made by compressing the gas until it "freezes" into a solid mass. CO2 is a rather unique substance in that it goes directly from a solid to a gas, which means that you can simply set a block of dry ice in your growing environment and it will slowly "boil" off CO2 gas.

One pound of dry ice is equal to one pound of liquid CO2 (bottled). One Pound of either is equal to 8.7 cu. ft. of gas.

If you drip vinegar onto backing soda you will produce CO2 as well.