Well I have a didgital co2 meter that registers to 10000ppm, I got room to 10000 ppm and held it there for five hours, low and behold spider mites still alive like nothing even slowed them down. People say this works, but I am having trouble getting them to die. I can get to 10000ppm in 18 minutes then holding it is no problem. Should I try longer time?? Expensive equipment just was hoping for suceess and not the bug spray bottle. Thanks for any input.