Easy CO2 System

Discussion in 'Do It Yourself' started by Ghost Grow, May 20, 2010.

  1. #1 Ghost Grow, May 20, 2010
    Last edited by a moderator: May 20, 2010
    I was interested in getting some CO2 into my grow room since the ventilation is less than ideal. A tank seemed too expensive and prohibitive for a novice grow, and drip systems are complicated to maintain and not steady in release, so I finally settled upon doing a yeast system.

    This is not anything I came up with myself, but I haven't seen it on GC before, so I thought I'd post my implementation/take on it here.



    Liter Bottle
    Dry Unactivated Yeast
    Warm Water
    Air Tubing
    Sticky Tack

    First fill the bottle with a mixture of warm sugar water. Next, add the yeast and shake the bottle up. Finally, drill a hole in the cap, insert the air tubing, and use the sticky tack to seal the hole between the cap and the air tube. Every three days, dump half the water, add the same amount of warm water, as well as five tablespoons more of sugar. This will continually produce CO2, which you can see bubbling out.

    Advantages are that this is cheap, quick, easy, and less fussy than other methods. Disadvantages are that CO2 amount is still limited and for larger grows, this is less practical.

    Especially since I can't vent my room, this has prooved pretty helpful in the grow and I've been glad I implemented it. Remember to put the end of the tube above the plants since CO2 is heavier than air and floats down.
  2. Have you tested this to see how much C02 is actually produced?
  3. it will depend on how much yeast you ferment. this is mainly for closet grows with poor ventilation to introduce ample amounts of co2. this is good for 4 or 5 plants and showed noticeable improvement in my grow. hope that helps!:hello:
  4. Awesome bro. + rep for your cool idea. Ima write down how to make one for myself. Hope it works good.:metal:

  5. this looks perfect for what i'll have going on...thanks for posting. where did you get the twisty tube thing?
  6. Help buds grow while brewing beer at the same time.

    LOVE IT!
  7. how do u take a poo in there??:confused:
  8. #8 justmeagain, Jun 29, 2010
    Last edited by a moderator: Jun 29, 2010
    I hate to bust the bubbles on this but......

    I have been making wine for over 30 years which is done in 5 to 10 gallon batches and the Co2 it produced was not high enough to promote plants growing.

    The wine making made the house smell better

    The 2 liter bottle might produce enough Co2 to gain some ppm if used in a sealed pc box grow

    A small fan blowing on low across a plant gives a better benefit then a 2 liter bottle of yeast

    I will believe this when someone shows me a ppm meter of before and after the yeast bottle was started. The size of the closed grow, etc etc
  9. im going to have to agree with you,

    In a 2 liter bottle the most sugar you can have is about 1.5 pounds. I am not really sure if Bakers Yeast can break down that high of a concentration. Maybe with a Turbo Yeast you can squeeze in 2lbs. The conversion from sugar is 51% ethanol / 49%Carbon Dioxide (theoretically. with perfect conditions) leaving you 1 pound of co2, released over a week. I don't own a co2 meter nor have i ever used a co2 system but honestly, that doesn't seem like enough co2 to be worth the trouble.

    I know everyone wants to do everything possible to help their grow, so i doubt you will give up this practice no matter what i say so let me give some other advice. :hello:

    1. yeast doesn't eat sugar. you need some type of nutrients in there. Molasses works well and makes the house smell like baking cookies.

    2. if you invert your sugar first the yeast will break it down easier.
    Boil your sugar in some water and about a teaspoon of lemon juice until golden. :)

    3. PH your sugar solution to 6.5 or so. it doesn't have to be exact just be sure it is not to high. Ammonia can be formed at high ph levels.

    4. If you aerate your water prior to seeding the yeast colony will replicate faster. the shaking from mixing the sugar and nutes should be plenty.

    5. Yeast is a fungus. By bringing it into your growspace you invite all kinda of nasties to grow. Always water filter co2 exhaust. Put the tube in some water.

    one way or another, good luck to ya brother.
  10. I guess a pound of Co2 would be about .4 cubic meters. That isn't very much co2 from a pound of sugar, but better than nothing.
  11. yea, honestly as the OP here, i have to comment that while i originally thought i saw an improvement in my grow, i really didn't quantify it well, so it's hard for me to support this.

    however, theoretically in a small grow room with *NO* ventilation, having that co2 bubble up in there is fine. your comments about the limit of co2 production are true, but that's why you change part of the water and add more sugar every few days:wave:. the truth is that in most novice grows, the limiting factor is not co2 but light, nutrients, etc. however, in a room that cannot be ventilated, a source of co2 is important during the daytime and IMHO should not be overlooked.

    as a side note, i just harvested all my strains, and they are looking extra tasty. even i even get one more puff because of the co2, it will have been worth it.

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