Yes, even breathing in your grow room will be beneficial. a nice way is to mix yeast, sugar & water in a bottle and vent the O2 to the plants. do a search on it
Some people (not me) water the plants with sugar water once every week or two. Not sure how effective that is, but it's supposed to help with giving the plants CO2
Some people (not me) water the plants with sugar water once every week or two. Not sure how effective that is, but it's supposed to help with giving the plants CO2
the can thing wont work. co2 is heavier than air, so it sinks. if u just opened the soda can and left it there, no co2 would come out, it would just stay in the can.