High Humidity Levels During Flowering

Discussion in 'Growing Marijuana Indoors' started by R00TER, Jun 11, 2021.

  1. I've got 2 girls at the moment in coco in the 3rd week of flower, everything is going very well but recently due to weather humidity outside has been super high and I'm finding my RH creep up quite a lot during the night.

    I'm growing in a decent sized room with intake/exhaust so my airflow is decent, 78f during lights on around 71f with lights off. I'm ranging from around 65-75% RH and I'm trying everything I can to lower it with little success. I've got a dehumidifier running, I'm also using some natural methods of dehumidification.

    I know this RH is not ideal for late flower and obviously my biggest concern is PM or mold of any kind attacking my plants. Will I be able to successfully flower these plants with these levels of humidity?

    If anyone has any advice or experience flowering in high humidity I'd really appreciate any advice
     
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  2. What size dehumidifier are you running. Running that you shouldn't have an issue with humidity if it's big enough. i run that in a 3x3 or 4x4. the extraction fan running full blast, blacking your room out and opening your tent, or maybe damprid. if your dehumidifier is big enough thats all i can think of


    Amazon.com: Shinco 1, 500 Sq.Ft Energy Star Dehumidifier, Ideal for Medium Living Room, Basements, Bedrooms, Bathrooms, Auto or Manual Continuous Drain, Quietly Remove Moisture & Control Humidity: Kitchen & Dining
     

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  3. It's about half that size, definitely am looking at upgrading the dehumidifer, thanks for the suggestion. I was also just mainly curious if anyone had actually flowered at 60% or higher and if it affects potency etc
     
  4. No one can tell you if you will successfully flower at that %. Any time during flowering when humidity is high plants are at risk. With plenty of air movement and tactical defoliation the risk can be less likely but there's still risk. The yield should be relatively close.
     
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  5. Gotcha, guess I will get a bigger dehumidifier and try and get RH down to around 50%
     
  6. 40% for flower.
     
  7. I use ultrasonic humidifiers to keep humidity around 65% from seed to harvest in hydro, and have never had bud rot.
    I do that to follow the unaltered VPD chart.
     
    • Informative Informative x 1
  8. Do you notice any resin loss on buds when flowering at 65%?
     
  9. if that was the best way to do it wed all grow like that js op
     
  10. I know what the ideal conditions are, but in reality you can't always achieve the ideal perfect conditions 100% of the time, so I was just curious to see how it would affect the final yield
     
  11. with the right equipment and an ink bird its easy to keep a good environment or hell just the right equipment i see youre getting agitated tho so you do you. good luck

    my tents stay perfect 24/7 365
     
  12. In all but my first grow or two, I've used the vapor pressure deficit chart, seed to harvest, so I've not compared.
    According to plant scientists, VPD is supposed to maximize plant growth.

    That growth maximizing doesn't stop at flowering.
    I expect 65% flowering to outperform 40% flowering, but I've not done the experiment.

    I believe "Low humidity during flower" is to avoid bud rot, not to maximize growth.
     
    • Informative Informative x 1
  13. so you disagree with the other guy posting in this thread? that's cool, it's nice to have multiple opinions and thoughts that's why I enjoy the forum, nobody is getting agitated my guy, strange you would think that but I guess it's all the way that you read things
     
  14. i dont disagree if thats what he does and has success. however if it was ideal everyone would grow like that. you seem to be looking for someone to say yea you can grow with 60% humidity and it be okay. just hate for everything to be going good until close to harvest and you lose some half or all your weed due to some guy growing hydroponics at 60%.

    even where he lives could play a apart in him not ever getting bud rot meaning his outside environment may be different than yours maybe he gets good genetics many factors can come into play that can differentiate a persons grow from one another.
     
  15. Yeah of course and don't get me wrong I appreciate you, let me try and ask a more constructive question to you. Do you think the main reason people suggest a sub 50% humidity during flower is bud rot? Is that the only reason?
     
  16. a wet environment creates mold if the buds stay wet mold can be prone. weeds grown all over the world surly as so in some of the most humid climates theres actually strains that are more mold resistant. but yea i would say thats the biggest factor im sure some growers think it helps density or what not I personally cant comment due to my inexperience in that kind of growing condition.
     
  17. There are some grow rules that are questionable.
    I suspected low humidity during flower was one of those, so I tested it.
    With excellent air flow and movement, high humidity during flower works great for me.

    Maybe I'm just lucky, but unless a lot of people have gotten bud rot from high humidity, then maybe rot is rare.
    Maybe worrying about it is counter-productive.
    That's what my 1-man, multi-year experiment with scores of different strains says.

    But everyone needs to try for himself.
     
    • Winner Winner x 1
  18. Inspect daily. First signs of mold, yank it or cut it out.
    Make sure you don't have any exposed wood around your grow.
     
  19. Brother I recently had issues with this myself, I had high humidity that I just couldn't keep down, I was sitting between 50-70% on a daily basis. I ended up getting bud rot which spread through my crop like wildfire, I lost one plant completely and most of the colas on the other two, I ended up pulling them early just to save some of my hard work. Do whatever you can to bring it down, open a window run the AC 24/7 whatever man, just make sure you don't have to go through the same pain I did.
     
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  20. Sorry to hear that man, what week did you notice bud rot?
     

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