Has anyone ever tried putting a tray of dry ice in their grow space for C02? I was thinking about trying that because its like pure C02 and it evaperapes into a gas. If you think its a bad idea tell me because I really dont want to fuck my girls up, thanks.
This idea has been fooled around with before. It could work, but there are complicating factors. First is the potential cost -- dry ice evaporates quickly, so all of that CO2 is released in a fairly short period of time, more than your plant can use, so there is a lot of waste and you will have to replenish frequently. Next, in order for CO2 enrichment to work you have to diminish ventilation (or you will just suck all your extra CO2 right out of the grow space), and that may be good for CO2 but bad in other respects. Another point is that CO2 builds up naturally during the dark period, so you probably wouldn't want to dispense extra CO2 during dark. There is such a thing as too much CO2 for a plant. Finally, you need fairly high temps and intense light for CO2 enrichment to be effective -- you need to induce the plants to "breathe" more heavily from the harsher conditions or they won't be capable of taking in that extra CO2. So, yes it is possible but a little tricky.
Im interested in this method too. Is there some sort of insulation, or container which could dispense the CO2 slowly? like a stryofoam cooler with some 1-inch or 2-inch holes to regulate evaporation rate. If someone were able to get this to work and increase their lighting and make the environment proper, do you think you could acheive much more than the seedbank stated yield for g/m2?