70-77% humidity when lights are off!!!

[therealoggrowerXD]

Hello,I'm in week 4_5 of flower , and when lights on I got 45-55% humidity, manageable. At night I'm at 70-78!!! I have 2 small dehumidifier running at night and a fan circulating air at night. My question, I know 75 is a lot, but if it's only at night , do you think it's ok? Thanks guys

 

[dextr0]

I think your waiting for some type of fungus infecting your grow. Get that humidity under control asap.

 

[Natep]

I would try and get it down.

 

[Thatoneguyyouknow_]

Is your exhaust fan running?

Cannabis tends to open all of its stomata for transpiration at night, it can more easily transpire and accumulate gasses at night when it's leaves are not being heated directly forcing moisture transpiration. Definitely need to keep exhaust going well. Any plant transpiration at all will raise the humidity.

That being said if it comes down during the day you probably wont suffer any consequences at all being honest. I grew for years before i discovered this was a thing that happens. You're really only going to have fungal issues if it stays up like that for extended periods and during warmer temperatures, or if you have a very thick entirely unkept canopy with lots of leaves transpiring directly against each other, or just too many top budsites crowding too small an area. The flowers themselves dont actually have all that much stomata if any, they mostly reside on the bottoms of the leaves. Moisture isn't going to accumulate in the flowers from humidity and transpiration alone in most cases (most).


And all that being said, def get that night humidity in check if you can easily do so. Bugs love that sh*t

 

[jetbtkng]

whats your set up, are u in a tent, whats humidity in your house or structure, if in a tent open the door/un zip it about 30inches at the top corner & have a fan blow towards the opening, thats what i do with my grow tent, 3x3x7, in my spare bedroom, keeping my temps between 69 at nite 80 day, humidity between 40 to 55, if i close tent up im up to 70+ humidity, i dont have any fancy plumbing in my tent, 1 fan, 1 humidifir, & i opened 1 vent at bottom & 1 on top side, & i open the door when too hot or humidity, as seen in pics below...

 

[therealoggrowerXD]

Hey, I'm actually just in a room with 2 lights and no tent, so I will look into an exhaust:) thx

 

[SnoopingAsUsualI]

Well the plant itself can withstand that for quite some time, there's rains in the wilds you know. Along with that, such a humidity is a paradise for mold and some fungus, also even if that is not the thing then the plants will surely suffer after few weeks of such humidity level so I'd say you need a good ventilation. Think of it, once lights are off - humidity is normal, meaning that the light vaporizes that. So you'd need a proper temperature and constant airflow, I'd say get a blower - the directed fan that can provide a good amount of air inflow, also will be a good thing to get the second one to such the used wet air out

 

[LoveGrowingIt]

@therealoggrowerXD - What is the temperature in the tent when the humidity is high?

 

[therealoggrowerXD]

@therealoggrowerXD - What is the temperature in the tent when the humidity is high?

29-30 celcius in the day, 28 at night

 

[LoveGrowingIt]

29-30 celcius in the day, 28 at night

I was thinking a temperature drop was causing the humidity increase, but probably not. RH does increase as the temperature decreases. I doubt a two-degree change would cause that much humidity change.