i must drop my 2 cents in here..

for starters the home brew is absolutley worthless, the amounts of co2 are not consistant enough, let alone high enough to make a difference, please dont waste your time

your grow must also be very stable to utilize co2, if your plants arent getting enough aeration, light, properly balanced nutes, and stable temps/ humidity, they wont be at peak photosynthesis to utilize supplimental co2

you also need to factor in how many people live at your house, most average family homes are at 600-1000 ppms, compared to the outside which can range from 300-600ppm's depending on location

also co2 isnt really that expensive, the average kit and 20lb bottle will run you 300, in my 4x4 room it last 2 weeks with it set at 1000ppm and its about $18 to refill it


the last thing i wanted to comment on is how to properly use co2, whatever ppm you plan on supplimenting it at keep it consistent to that #, ive read a few places where people shut off there fans and enrich co2 for a short period of time and then turn there fans back on, plants dont use co2 in burst, they use co2 as they need it, your going to get more results with a small amount enriched over the entire length of the photoperiod, compared to spiking the amount high and letting it drop, your plants will adapt to the amount of co2 in your room and structure there metabolism around that specific amount, thus why i stress a stable enviroment

in the end im a supporter of co2 enrichment, ive experienced nothing but good things, definatley higher yeilds, but the rate of growth is why i keep on using it, ive easily cut 1-2 weeks off my flower time by supplimenting co2 at 1000ppm