We used to use club soda to loosen the soil in outdoor plants. The gas is released and mixes with the outside air. Go ahead and use it water and you will get the affect of CO2 as spraying the leaves.
It's been 10 years since I've grown indoors and I'm setting up a vertical grow ing a six by six by nine foot room. I've been researching the octagon and have strongly believe that this is the wave of the future for indoor growers. Less energy use and better yields. All the indoors grows that...