When to Stop co2 Increase During Flowering?

Discussion in 'Advanced Marijuana Cultivation' started by Micobfsb, Nov 29, 2011.


    Thedillestpickle Well-Known Member

    I just added this thread to my favourites list...

    CO2 will not raise your humidity, if you use a CO2 generator(propane or natural gas burner) then yes your humidity will rise, but the same is not true for a CO2 ejector.

    During the last two weeks of flower its a good idea to lower your temperatures so that you dont volatize the very nice aromas of the bud. You can keep running them high for the sake of yield but for higher quality you should lower temperature to normal levels. Now that your temperatures are back at normal levels theres no need for the extra CO2.

    Flourecents can be used in conjunction with CO2 but only if you have alot of light, Usually if your running that much light you have invested in a HID, but some people will run alot of light using just flourecents. This myth is actually stated with no explanation in the growers bible by Jorge Cervantes, His book is alright but its full of misinformation

    Hopefully Im not full of misinformation(bullshit), everything I just typed is speculation
    Dr. Who likes this.

    IVIars Active Member

    By decreasing the co2 levels toward the end, i believe it stops ethylene (sp?) production and begins ripening it.

    Warmer temps when running co2, 80 and above.

    Too much humidity cause the trics to become elongated and make it easier for them to snap off

    xmatox Well-Known Member

    Lol. You're funny.

    DirtyEyeball696 Well-Known Member

    I use co2 all the way until the last 7 days of flower. The biggest thing to keep an eye on is the humidity. 45-50% is optimal

    Kush is My Cologne
    Dr. Who

    Dr. Who Well-Known Member

    KEEP IT BELOW 70F or risk loosing everything to root rot!
    Dr. Who

    Dr. Who Well-Known Member

    You stop at 2 weeks left so the ethylene gas starts to be expressed by the plant to actually ripen the bud! It is connected to the bulking phase and if you don't stop it's use (CO2) the plant will take longer to actually ripen and it decreases the potential yield!

    The use of CO2 in veg is NOT worth the cost of doing it! Sure your supplier is going to say to! He's the only one actually GETTING any "profit" from it!

    You read above right?

    And you guys believe this SHIT! For god's sake you don't even go out and find the truth? Best info on this subject is in Ed Rosenthals book "Marijuana Growers Handbook" PAGES 131-142 and 192-193.

    Did you read everything to this point? DO IT!

    What crap! Running gas in veg is THROWING AWAY MONEY!

    GAS OFF FOR THE LAST WEEKS - Nothing to do with "OILS"....... YES! Higher temps and RH in bloom for gas to actually WORK right! I run 1300ppm with about 85- 87 F and 70-80% RH. You cool to normal at lights out.

    What the fuck? This is BULL SHIT of the highest order! Please list your source for this - I want to know!

    EW, EW,,,,,SO close! "starts" the ethylene to become effective at ripening!

    I might start at 80 F for 1150 ppm and have 85+F by 1300!!!

    WHOOPSY! Wrong answer! You MUST run higher RH right along with the higher temps to maker the high ppm rates of the gas to BE effective!

    I hope you all read your personal answers!

    Here is an example :

    Your running, oh lets just say 1500ppm of co2 - to make the point here..
    You have 5000 lumins of light (645w per square meter)
    Your temp is 70 F
    The plant is only up-taking or "using" 800 of those PPM!!!!

    OK, same set up BUT,
    Your temp is 85 F
    The plant is now up-taking 1300 of those PPM!!!!!!

    NOW THEN: A word on higher RH with gas use.

    Alright then guys and gals Have you ever heard of the VAPOR PRESSURE DEFICIT?

    I borrowed this for my ease -

    RH has an ever more direct effect on plants. Plants need to "sweat" too - or rather, they need to transpire (release water vapor through their stomata) in order to grow.

    The amount of water plants lose through transpiration is regulated, to a point, by opening and closing their stomata. However, as a general rule, the drier the air, the more plants will transpire.

    RH has an ever more direct effect on plants. Plants need to "sweat" too - or rather, they need to transpire (release water vapor through their stomata) in order to grow.

    The amount of water plants lose through transpiration is regulated, to a point, by opening and closing their stomata. However, as a general rule, the drier the air, the more plants will transpire.

    TAKE a LOOK at this chart!


    Now while I run only 45% RH at say 75 F with NO gas.
    When I run gas, I have to be FAR, far closer in the VPD for the co2 and plant work at it's best together!

    CO2 increases uptake. This means your getting more nutrient, right along with that water!
    By this factor of increase (about 30%) you NEED to balance much closer that VPD to not begin to feed too much.

    When I run my generator. I have a temp of 85-87F and an RH of about 70-75 during gassing hrs...

    Understand this ?

    PLENTY of scientific PAPERS available on the web to read on exactly this subject and it's parts described here!

    Start looking!
    CaptainCAVEMAN likes this.
    Dr. Who

    Dr. Who Well-Known Member

    You better read the above post as punishment for duping me into answering a 4 year old post! You should find your RH is too low!

    thewanderingjack Well-Known Member

    And thats a big yes because:

    Except not begins, allows to begin... CO2 inhibits ethylene production, a fruit hormone/pheromone that induces ripening and is produced by ripening plants. Transport trucks use low temps and CO2 to transport produce to reduce the risk of spoilage.

    "one bad apple spoils the bunch" is a metaphor based on this literal effect.

    p.s:. remove ripening fruit from other fruit, preferably completely away, to extend the other fruits life... a ripening fruit will ripen other fruit.

    you don't ventilate well in and around each plant... I run that high or higher (my environments very wet) and only have problems when I have overlaps or just not enough air circulation... both by pulling branches out via LST and by having a nice fan blowing. I just went through my plant super close... only problem I found was where a plant had had a branch up against the wall (just a small spot).
    Last edited: Aug 3, 2016
    Dr. Who

    Dr. Who Well-Known Member

    You do know I was talking about DWC right?
    One day you'll hit a strain that will NOT hit a 70F res temp without getting root rot. Can you say Bomb Seeds? That's just off the top of my head.......You do not allow res temps to go over 70 F....general accepted temp across the board....

    thewanderingjack Well-Known Member

    Hah, I did do and had forgot... so yeah... I should sleep... it's been a while. :-D I'm sure I was even referring to bud rot.

    Root rot, in DWC, I know nothing about... but just to note: in soil, it is just as serious... most people in general, and newbs in particular, "over water" and wind up drowning their plants.

    Thanks for the heads up :-D... hate to be accused of talking out my ass (and having it be true!)
    Dr. Who likes this.

    b4ds33d Well-Known Member

    the bro science is strong with this one.
    Dr. Who likes this.

    powerslide Well-Known Member

    2012 brought back to life to call some dude out and disappear. Nice

    xmatox Well-Known Member

    Disappear? He never responded to me probably because he was here for about a day and left. I did however bring back this thread from the dead. My B bongsmilie

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