Humidity related questions

so where i live is hot and humid, humid all the time, even moreso after a rain. hot 75% of the year. according to google, the average humidity here (in east texas) is approx 65%

from research i have done, seems bud rot likes to happen where there is high humidity. from what i read, under 50% humidity and bud rot is not a concern.
i intend to make a charcoal filter for the air inlet to the tent specifically for trapping moisture in the air going inside the tent.

what is the optimal humidity levels for the strains i am growing?
blueberry (AF), northern lights (AF), amnesia haze (AF)

does humidity level matter at all stages of growth, or only during flowering?

anything else i need to know about humidity?

TIA for responses and questions answered

Yes, definitely but not by strain.
Seedlings 65 - 80%
Vedge 50 - 70%
Flower >50%

Aim for the above and you should be fine. In flower, yes its better to have a low RH


Another critical factor is adequate air movement. Fresh moving air allows the plant’s transpired moisture to evaporate quicker.


Scowners covered here, and beardless
For flowering I shoot for 40% or less.


You can check out VPD - Vapor Pressure Deficit. There are lots of published charts giving humidity levels at given temperature points based on the plants life phase.


Yeah. Deffo what @beardless said on both.
You can go either way and balance RH vs Temps etc. Its pretty flexible as a plant and isnt called weed for nothing :slight_smile: but like anything, there is a sweet spot for the best results on that and PH, TDS and so on. There are people that have temps in the high 80’s permanently and still produce nice harvests and I have personally grown plants by just chucking a seed straight from a packet into the soil and left it to do its own thing and just gave it tap water (mine is between 7.3-7.5 PH) and I got a nice plant.

However, the advice you can get here comes from some very knowledgeable people and almost everything I know is because I read the forum posts and have asked questions and when following their advice, I’ve never gone wrong.

THANKS TO ALL OF YOU, I APPRECIATE THE INFO!! since i have sank so much money into this, i cant afford to screw it up. usually when i spend this much money on something, i have to gas it up drive it home… when its all said and done, i will have spent nearly 2k on growing, not counting electricity

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Sometimes you know you are doing the right things but its always good to know someone else agrees :slight_smile:

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I’m gonna suggest you just cut to the chase and buy a dehumidifier. I chose one that has an auxiliary drain hose so I can run it all the time in flower. It’s really the only way you will be able to maintain lower RH in flower IMO.

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Yes , I sometimes need that verification.

Hello growers. Can’t seem to get humidity below 50% even with the dehumidifier. Fluctuates between 50-60. Plants are now in full flower mode. How likely that bud rot takes place? I do have two fans blowing continuously. Can’t run AC continuously for obvious reasons. Will bringing RH down for a few hours during the most humid times with the aid of the AC be beneficial or the fluctuations causing more harm?

Always great to learn from the vets.

i googled VPD and couldnt find many charts that were legible, the ones that actually were legible were not very detailed and not specific to weed. could you please give me link to where a good one is (specifically for growing bud), a site that explains how to understand it and so forth? i would appreciate it very much!

Here a couple. I use scynceled. It is straight forward and gives me a target. I try to get as close to it as I can

thank you very much!!