Ill be 100% honest, I used the method with champagne yeast and a 5 carbon sugar(Corn Syrup) in a 5 gallon bucket just as the original post suggested with a 20 - 25% solution of syrup to water... Allthough the amount of CO2 I produced is unknown I did make some nasty wine smelling water. I use a CO2 tank, and i understand that this is a cheap way to make your co2, but in all honesty I dont see it as being practical for larger grow ops, at the cost of the syrup $15 per gallon and 90 cents per champagne yeast packet, the device only make CO2 for a little over 2 weeks before becoming useless... By the time my crop would finish I would have spent enough money to purchase a CO2 tank and not have to worry about the CO2 bucket.

Some people were asking in previous posts, When do you add CO2?

I only use it for flower, allthough im sure some sneaks its way into the veg room, but I use CO2 to up my yield in flower, not my veg. You can take your plant from producing 1 - 2 ounces and increase it by up to 1 1/2 times.
Ive heard some people getting up to 4OZ from a single plant using co2.... but I have yet to accomplish that.