Originally Posted by Douglas.Curtis
I've gotta dig up the thread. The concensus was 100% CO2 is bad for the plant after a few hours, while helium didn't seem to bother them.
I used pure CO2 to kill fleas, and it's similar to killing spider mites.
The amount that will kill the spider mites is not good for the plants.
The old chemistry gas formula is helpful
PV = nRT
P ~ pressure
V ~ volume
n ~ number of moles of gas
R ~ gas constant
T ~ temperature in absolute terms.
& the units have to work out. I used 4 pounds of CO2 to gas a twin sized mattress.