Hi.. You would get a terrible smell (I think ). A normal grow space has 300 PPM of CO2 in the air. Optimal amount of CO2 for growing is 1500 PPM (5 times as much). It really depends on the size of your room and how much CO2 you can produce.. Yeast, sugar, water or dry ice usally isn't useful, unless you have a really small grow space! Good Luck!
Using CO2 to boost your grow is a great idea. In the article I copied and pasted here, they are talking about pushing the normal 300 or so parts par million of CO2 to 1500 in an 8 x 8 x 8 room (feet) As you can see, this is double the size of a closet and they are talking about a 16 gallon 45 pounds of sugar cocktail! Anyway, check out this product if you are trying to cheaply improve your CO2 levels in a small space. ExHale CO2 Bags at Planet Natural It is widely known that CO2 is a byproduct of fermentation. CO2 is the gas found in bubbly beverages, such as champagne and beer. The same process that "carbonates" these beverages can be harnessed to create CO2 for a grow area. A pound of sugar will ferment into approx. 1/2 lb of ethyl alcohol and 1/2 lb of CO2. We've determined that we need 0.8 cu ft of CO2 for our 512 cu ft grow room (see above.) Then calculate the size container needed by dividing the size of the grow room by 32. 512 / 32 = 16 gallons. (A tall kitchen garbage can would make a good 16 gal. bin) Assuming that the bin will produce half alcohol and half CO2, the bin will consume .16 lbs of sugar every four hours, which is roughly 1 lb per day. This means that about 45 lbs of sugar will be used over 6 weeks (assuming that not all sugar is completely converted to alcohol). To get the process started, mix a pinch of yeast, 12 ounces of warm water and a half-cup of sugar and keep warm and covered until bubbles form in a day or so. Use this mixture to inoculate the main bin. To create a yeast bin mix, dissolve 3 lbs of sugar per gallon of boiling water. Cool the mix to 80F before adding the yeast. Locate a container with a tightly fitting lid. The lid should be equipped with a hose to direct CO2 gas towards a fan for distribution into the space. Increased air pressure in the bin will force the gas out of the hose. Both canister and lid should be thoroughly cleaned with hot soapy water and rinsed well before use. Start off the bin a little more than half full (10 gallons of water and 30 lbs of sugar). Every week, add another gallon of water and 3 lbs of sugar. The yeast bin must remain at 80-85F for the reaction to continue. To monitor activity and prevent contaminants from entering the bin, create a fermentation lock by placing the end of the hose into a glass of distilled water. The bubbling water will be an indicator that there is still a reaction in the bin and prevent bacteria from entering the bin through the hose. Our bin will need to be completely replenished every 6 weeks, or when the bubbling slows. A simple taste test will tell if the bin needs replenishing. If the taste is sweet, there is still sugar in the water and the reaction should continue. If the taste is dry like wine, the bin is mostly alcohol and should be replenished. Some growers preserve a cup of liquid from the old bin and use to inoculate the new bin, however if an infestation is starting to occur, this can contaminate an otherwise fresh bin with bacteria. It's just as easy to inoculate with new yeast as above, and extra yeast stores easily in the refrigerator for months. Corn sugar (available at wine making shops) is a less expensive fermentation medium than regular cane sugar. Other fermentation mediums can be used depending on materials cheaply and readily available to the grower. Corn syrup, maple sap, even old fruit juice can be fermented, although with increased odors and more waste cleanup when the bin is refreshed. Advantages -Easy to create with simple materials -No safety dangers -Inexpensive materials when purchased in bulk (sugar) -Ethyl alcohol byproduct can be siphoned off and burned in alcohol lamps for supplemental CO2 enrichment Disadvantages -Difficult to regulate -Fermentation can produce odors -Large yeast bins are heavy and hard to move.
Home brew CO2 and other cheap methods of producing CO2 from a chemical reaction all do in fact make CO2. The problem: They tend to make CO2 one hundred times too slow to keep up with room ventilation. Every time your ventilation turns on, all the enrichment is sucked out instantly. To reach enrichment levels again, it will take hours. The folks selling gimmicks like Exhale, Green Pad, Boost Buckets and others, all do tests without ventilation. So if you have a very small room that never needs ventilation, then perhaps it might work. 99.9% of the folks on this planet need to have some sort of ventilation. Turning the ventilation off is not the answer (unless runnning recirculating AC in a sealed room). "Do compressed CO2 and CO2 generators work?" Compressed CO2 can put your room back to enrichment levels within a few seconds of a ventilation cycle. Most CO2 generators make CO2 very fast as well, but tend to be slower then tanks. They are the only real answer to CO2 enrichment. Bottom line: Don't buy into home brew or any of the cheap gimmicks. They simply don't work.
Thank you all for the input. I'm growing 1 in the kitchen cabinet with a 300w spiral cfl Ill try the homemade co2 for a couple of weeks to look for foliage changes.