C02 Calculator ~ Calculate How Long to Run your CO2 Tank

Discussion in 'Indoor Growing' started by kskid, Sep 30, 2007.


    hammer21 Well-Known Member

    Carbon Dioxide's Role in Plant Growth

    With respect to CO2 utilization, plants are divided into two types: C3 plants and C4 plants. These names essentially distinguish two types of photosyntensis. C3 photosynthesis (so called because the photosynthetic process yields 3-carbon derivatives) has a problem in that sometimes O2 fills the role that CO2 is supposed to fill. When it does, much of the energy that goes into photosynthesis is wasted. C4 plants, on the other hand, starts with a gate, of sorts, that keeps much of the O2 out, so this waste happens less often.

    Most plants, including plants used in agriculture, are C3 plants. This includes lemon trees (virtually all trees, in fact), sugar beets, and potatoes. Corn and surgarcane are C4 plants.

    Each type of plant reacts to a change in CO2 concentrations differently. C4 plants already use CO2 efficiently. An increase in the concentration does not help them much. C3 plants, on the other hand, benefit greatly from increases in CO2 because less of the inefficient O2 photosynthesis occurs. Plants in a high CO2 environment increase their plant mass by 20 to 25%. Yields of some crops can be increased by up to 33%. This is the effect of doubling CO2 concentrations over Earth normal. Still higher concentrations can be expected to yield still better results.

    Note, however, that the effects vary even among different types of C3 plants. Some are better able to take advantage of higher CO2 concentrations than others, and a few actually suffer if CO2 concentrations are raised.

    But, there's a catch. These benefits occur only if the nutrient levels and the amount of water available also increase. CO2 alone does very little good. Consequently, to take advantage of a higher CO2 concentration, we must supply more water and bring in more nutrients (such as nitrogen).

    In fact, there is more than one catch. As a plant's production of starch from CO2 increases, it seems to reach some sort of saturation point. It reaches a point where it can no longer take advantage of the greater abundance of CO2. Scientists suspect that this is because there is a bottleneck in the plant's metabolic system. It can manufacture more starch, but it can't get it to where it is needed - or it can't use what it is getting. At this point, you might as well bring the CO2 concentration back down to normal levels for all the good you're doing. Or, if this point is close to the plant's maturation point, you can harvest it and plant the next crop.

    [Note: high conentrations of CO2 allows the plant to use water more efficiently. This is because the passageways that allow CO2 into the plant also let H2O out. Under higher CO2 concentrations, these passageways can be kept more tightly constricted, allowing less H2O to escape. But there is a tradeoff here between CO2 fertilization and efficient use of water. To the degree you have one, you must give up the other.]

    TheGreenGlove420 Member

    So why dont you use paintball co2 tanks, got any laying around anywhere, i filled em, three 20 ounce tanks with smart valves, so i can open and close with ease, if you have good strains 2 lb tanks are not needed, put in fresh outdoor air and use small tanks if regulated properly, will have fantastic results, or you can just grow outdoors where everything cheaper, ha, but yeah if you wwant monsters indoors, yeah forsure you need excessive co2 1800 ppm a day roughly.

    Ammastor Active Member

    I like the calculator. Also love that it tells you how long the 20lbs tank will last. good to know so you know when to reorder.

    duece513 New Member

    Just a quick questionÂ…I have a gas furnace and a gas water heater. Both are in the same room as my forest..will my plants get Co2 off these?

    Javadog Well-Known Member

    Those devices should be venting their own gasses separately.

    This is a safety precaution.

    Good luck,


    junker1 Well-Known Member

    Has anyone heard about using a propane mosquito catcher in a grow room?

    maxomin New Member


    GSchwartz New Member

    GREAT calculator
    White Penny

    White Penny New Member

    Thanks for this

    zhzzhg New Member

    Moving to indoor growing to be stickied, good find!! [​IMG][​IMG]

    mc130p Well-Known Member

    Hey all, random question here about CO2: If you could only have CO2 for a single ~4 week time span on a grow, when would you time it?

    I think I would do it at the beginning of flower, but I was wondering if any of you had an opinion. Basically, I hate the idea of just letting compressed CO2 into the air, so I want to use only one tank per grow in the most optimal way. A 20lb tank typically lasts me about a month.

    arhdhath New Member

    Moving to indoor growing to be stickied, good find!! [​IMG]

    postnothrills Member

    Isn't CO2 related to temperature? If your temps are low, the stomas open up, right?

    LifeisAx3 Member

    Has anyone had experience with a Uvonair 1000. I know it emits co2 just don't know how much at a time.

    Javadog Well-Known Member

    I believe that that emits O3 which is very different from CO2

    Ozone is a good odor eliminator. It works by causing particles to
    clump together IIRC.

    It will not enhance a grow in any way that I understand, but it can
    help control odor.

    Cana Cultivator

    Cana Cultivator Member

    using a bottle just isnt efficient enough... you all are thinking on too small of a scale....

    RockinDaGanja Well-Known Member

    Woops! According to this calculator i been using about twenty to twenty five percent more then i need. thanks a lot ks...you just saved me money. Most importantly though qaulity of these ladies in my room!!!

    ledcflgrow Member

    I get great yields and dank weed. My IB tested at just under 24%. I put my co2 on a timer. It is off when lights are off. Then when lights are on, I have it kick on for 30 minutes every 3-4 hours. I think it is set to 4 right now. During flowering, I pump it to 3.

    I leave it on very low, so the highest the ppm gets is 1300. It drifts between 800-1300 while lights are on. I get great results with this and a 20lb tank last me a month or two.

    Botonist Active Member

    Thank you, that helped me out, will save lots of wasted co2.

    papapayne Well-Known Member

    what kind of timer do you use?

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