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Cheap Way to make CO2 for your grow

Discussion in 'Newbie Central' started by rollitup, May 17, 2006.


    rollitup Forum Admin Staff Member

    This is a low budget mod that can help you produce CO2 by simply using vinegar and baking soda. This method eliminates excess heat and water vapor production and requires simple items you can find in your closet :twisted: Create s system that drips the vinegar into a bed of baking soda (place it in a bucket) The main con of this system is not being able to control the CO2 levels, It takes alot of time for the CO2 to build up to a level where it helps a plant. Once this level is reached going over this level can kill the poor little plants :) this will take some experimenting on your part to figure out how much to add, throwing a solenoid switch in the line with a timer will help you do this with little effort.

    Good luck happy smoking
    Sure Shot and highflyby like this.

    Anonymous Active Member

    Baking soda/acid is a good system, but it is ultimately fairly expensive. Furthermore, you also release acetate ions/salts, as well as other volatiles from the vinegar (which is not a pure solution of acetic acid, of course). They prolly won't kill your plants, though they might. Instead they will likely make it smell or taste bad.

    What is a better way to get your carbon dioxide? Fermentation. Acquire some brewer's yeast if you can. The types of yeast you can use are in order of what is best, though all are acceptable:


    Rig up a simple fermentation chamber with airlock. The airlock is designed to keep the atmosphere anaerobic while releasing your good CO2. Fermentation chamber should be any airtight container with top. It could be a 2 liter Coke bottle, for example. Drill a hole in its top and glue in some plastic tubing, making sure to create a good seal. An epoxy is prolly what you'll need to do it. Run that tube into a smaller, halved bottle: a water bottle works well. Place the tube at the exact bottom and glue it there such that the outlet of the tube faces the wall (not the bottom) and is not blocked (by glue, the wall, your mouse, whatever). Fill that up with water, about an inch and a half above the bottom.

    The mechanism is all set up, now set up the fermentation. Fill the bottle with about a 20% solution of glucose (dextrose) by mass and place a few tsp. of yeast in that jaunt. Placing the yeast in some warm water for half an hour prior with some sugar is a good way to jump-start the process. Using those six-carboned sugars, you get optimum results, but other sugars can be used. In general, you'll likely find the 5-carbon variety (fructose: corn syrup, eg.) or the polysaccharide (sucrose: cane sugar). In these cases, its ok to add a little more sugar, no more than 25%. Champagne yeast can tolerate more. Brewers yeast, you may want to shoot for less. Cap that jaunt with the tubing/cap system you rigged up.

    Here's the principal, its perty simple: The yeast use the sugar to make their energy (ATP). However, in absence of oxygen, the metabolic pathways can't be completed, and alcohol is excreted as waste. This is disadvantageous to the yeast, but hey, who cares? They also release carbon dioxide. For every equivalent of glucose or dextrose, the yeast produces two equivalents of carbon dioxide and alcohol. If other sugars are used, the process is slightly less efficient due to the early metabolics that get done to prepare it, or the inefficiency of metabolic/synthetic shunts (biochemical shite, its unimportant, but fun if you are nerdy). The carbon dioxide is good for your plants: its the objective. The alcohol is bad. It increases in concentration in the fermentation vessle and DOES NOT leave in any way. Over time, the yeast poisons itself with its own waste. Better yeasts (as per the above sheet) survive longer and make more carbon dioxide. Hence the reason for increasing the sugar, if you'd like (the difference is probably just about marginal if at all, so don't dwell on it).

    So what does this mean for you? A mole of glucose is around 180 grams. Thus, a 20% mass solution will produce slightly more than TWO MOLES (2.2 to be be exact) of of gas per liter. At standard temperature and pressure, and if you are growing, that's what you want, you will get around 50 liters of pure carbon dioxide from this method, over the time period of about 2-4 weeks. Great stuff.

    Problems: You can tell the yeast are dying when the bubbling through the airlock subsides. No way around it, you need to whip up another fermentation mixture. Optimally you would do this every week and a half, while the yeast are at their maximum productivity. Using cane sugar and baker's yeast this is a crazy inexpensive endeavour.

    Can you kill the plants with too much CO2? Most likely not. They breathe it as air, and they really only need oxygen (the only other thing they really take from the air) to run their ETC and some other minor metabolic processes. They get this from the water, believe it or not. Also they respirate as much 02 as they take in CO2. No problem, really. Time when killing the plants from carbon dioxide have been reported is likely either in extreme cases (approaching NO oxygen in the air and thus water) or due to the poor downsides to using other carbon producing methods (acidic air, contamination of various sorts, etc.). On the other hand, your plants would optimally have about 3 times as much carbon dioxide as would be in the atmosphere. That rings in at around 6%, so not that much, and in all likelihood, its gonna be difficult to bring it up to these levels. Happy planting.

    rollitup Forum Admin Staff Member

    Good plan guest, if you signed up I would have given you some reputation points to play with, when you come back just pm me your username.
    stoner in WA likes this.
    Little Tommy

    Little Tommy Well-Known Member

    Here is a picture of a simple fermentation setup that I have used. I keep a towel wrapped up on the outside of the glass. The yeast seem to work better in the dark.

    Attached Files:

    highflyby likes this.
    Florida Girl

    Florida Girl Well-Known Member

    I love the simplicity and inexpensiveness of this method and would like to use it in my 4 x 4 x 6 grow tent when I get to the flowering stage.

    Can you tell me about the smell? Is it god awful or just slightly unpleasant? Also, does it attract fruit flies or other tiny gnat type bugs?

    Thanks :)
    Little Tommy

    Little Tommy Well-Known Member

    I like the smell. It smeels like making beer. I happen to like it though my wife says it smells like a mild fart. No bugs ever noticed being attracted to the setup.

    ctech4285 Active Member

    i think CO2 becomes toxic for plants above 5000ppm, btw there is a cheap 100$ CO2 meter on ebay (without display, need too hook it up to your computer, search CO2 controller)

    anywho im gonna try the fermentation method and keep a record of CO2 levels if there is interest for this data...

    Hags Well-Known Member

    whats the purpose of the airlock? couldnt u just run the tube straight out?

    mountaindude530 Active Member

    you have to seal the top with the tube coming out of it.. what happends is the yeast feeds off the glucose (sugar) in order to make energy.. it produces the co2 as a byproduct and heat is released.. co2 is heavier than air and so the heat helps push the co2 up the tube and above your plants.. so you have to seal off around the tube so that the heat won't just escape..

    just for general knowledge: the normal concentration of co2 in the air we breath = 300 ppm.. optimal plant growth is 1400 ppm.. at 1500 your starting to stunt plant growth and once you reach 1800 your killing plants and it's no longer healthy for you to breath either.. hope this helped
    stoner in WA likes this.

    andrewpnc Active Member

    Where did you get that big ass glass jug! i have to get one of those!

    johnnyfly2009 Active Member

    whats up guys here in ny tryin to grow some chronic any pointers wud b nice thanx

    SayWord Well-Known Member

    great info! good to know +rep for u my friend

    needhelp Well-Known Member

    i use the sugar, yeast and water in a bottle thing like mountaindude... just drill a very tiny hole in the top and CO2 releases slowly over 2 weeks.... shake up the bottle for a burst of CO2.... you can actuallly see all the tiny bubbles rushing to the top and you you start to smell the yeast... so i know it works... plus their where days when i would go look at my plants 24 hours later.. and they appeared a darker green then before

    blzbob Well-Known Member

    How much sugar yeast and water did you use?

    sycocid Active Member

    why not just make some wine if you are going to go through the process just to throw it out? What about using co2 cannisters for a bb gun? If you could say, puncture the tip of the cannister and allow the gas to slowly escape while setting it under the plant(s)? Of corse I would only do this in a confined area with no fans etc,.

    ELee Well-Known Member

    I have also heard of using Seltzer water. but I'm not sure how to use it!

    needhelp Well-Known Member

    its called a CO2 generator... you can google it..... you get a 2 Liter soda bottle...2 cups of sugar, 2 cups of water, 1/4 teaspoon of yeast.... dissolve the yeast in 1/4 cup of WARM water...not HOT..... and after that mix everything together.... make sure you use a soda bottle because soda bottles are flexible and are made for CO2 buildups...... and also drill a tiny hole in the soda bottle cover before you start the process.... because if you don't.... the bottle will explode from the CO2 buildup

    needhelp Well-Known Member

    you can use Seltzer water but i didn't want to mention it because you have people on here who swear you shouldn't give plants Seltzer water and they say the roots don't need CO2, just oxygen.... when in reality they are WRONG... I am not an expert grower but the reason i know they are wrong.. 1) i tried it and it didn't harm my plants at all 2) i looked up a study done with 2 plants Water Vs. Seltzer Water... it showed a chart and the experiment was done over a series of months...so it wasn't a bullshit study... and the plant fed Seltzer Water actually grew healthier and bigger than the plant that was fed water... (it even became smarter.... meaning... when certain leaves started to die when they conducted a dry experiment... the plant started to grow leaves at the bottom instead of the top like every plant that is fed water) because the theory is since plants roots do need oxygen... the bubbles are feeding both to the roots and people didn't know roots can benefit from CO2 because of the whole plant leaf using CO2 thing.... and what was also a plus sign... the bubbles help loosen dirt around the plants roots so they do have the room to breathe easier.... there are many that will dispute this... but like i said... i looked it up for myself because you can't depend on weed growers to know and understand all aspects of plant life.... you also need people who know plants.... just make sure its seltzer water with NO SODIUM... maker sure its all zeroes in the nutrional column on the back of the bottle.... oh yeah.... there are people on here that will say don't water your plants seltzer water...just spray it... i don't know anything about this or if it works... but i do know you can give your plant seltzer water as long as there's NO SODIUM
    stoner in WA likes this.

    needhelp Well-Known Member

    i recall people on here using the cans full of air.... i think one guy said he taped the handle down so it will give a slow leak.... i don't know how long it last for him..... puncturing a canister just seems unsafe to me.. thats pressure built up instead...

    weedyoo Well-Known Member

    made one of these after seeing it on here in another post any way

    you will need
    5 gal bucket with cover
    3 small plastic hoses
    5 lb bag of sugar
    if you want
    fish tank pump
    one of thoes fish rock that makes bubbles

    ok drill 3 holes in cover just the size of your hoses as they need to be sealed.

    four if you are using the fish pump. put all hoses thure the holes 3 inches glue or calk them sealed.

    same for the hose from the fish pump,but this hose run the the bottom. this comes on in the day light hours it sturs the water making more co2.

    now you run the 3 hoses up to the celling and down over the plants.

    only thing left is to make the mix

    fill bucket half full with water and 5lb sugar.

    make yeast as the derictions say to. slap the cover on and wait. this last me one week. hope this helps.
    highflyby likes this.

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