Humidity in flower

[Cali]

So I’m in flowering mode right now but I have been experiencing high humidity levels when the lights are off.. it blows up from around 30 to 45 rh then when lights out it goes up to the 70 to 85 rh so far no mold or anything like that but I want to know if that will affect my yield? Also what I can do to help keep it low? Any ideas please help I’m in dwc 5 gallon bucket..

[Campesino]

How do you vent the tent? Exhaust and intake...
What is your ambient RH?

[Cali]

I have a exhaust fan and just two small clip fans blowing thru my canopy it is well ventilated not sure what my ambient humidity is but in my tent in the day it’s at around 36rh at night it goes up to the 80s in there not sure why I have the exhaust fan running all night with my fans..

[Insight]

When the lights go off, the temperature goes down. Cold air holds less water so the relative humidity rises.

Can you increase the exhaust ventilation? Open more vents? Increase fan speed? Can you raise the temp a bit when the lights go off?

[Cali]

Will try to raise temps with heater.. any other suggestions?

[alltatup]

Dehumidifier! I'm in week 6 of flower right now, and my 50-pint dehumidifier is running all the time keeping the rh at 40%. I empty it 1-2 times daily.
I keep it at the door of my grow room so it blows the warm air out of the room.

[UrbZ]

If possible leave your tents doors open for the first 5 to 10 minutes of lights out. I battle the same thing. It wont hurt the light schedule and will keep your humidity from barely raising as the tent levels out to the rooms ambient RH and temp during this point.

I ended up buying a big dehumidifier to bring the room my tents are in to below 35 %. It helps balance overall rh in the whole enviroment. Air conditioner will also bring rh down and help keep your room cooler.

[Smokesteve]

A dehumidifier can be great I use mine on a timer it really works well.

[Trimmings426]

Dehu and maybe leave EXHAUST running I leave my door open for 10 or 15 mins like mentioned earlier that's really all I do and it keeps my th around 34% as supposed to 65, 70

[GreenhouseEffect]

I use a dehumidifier on a timer, to go on at night.
I grow in soil, so have been putting down some diatomacious earth for pest prevention, noticed that it seems to suck a little more humidity out of the air at night. Some people leave a bowl of rock salt in there flower tent, a bowl of DE might help, the stuff is really dry.

[D.A.A.S.69]

You gonna wake up one day an have mold on them, try to find a dehumidifier somewhere, soon. They are not that expensive, plus it will save your crop.

[BlueBudz]

Do you exhaust the air from your tent in the room your intake comes from? Do you keep exhaust fan on at lights out? You must know the rh of the air @ the intake. If u don’t keep fan on at night turn it on, if you exhaust back into the room move it out side. If the rh is high everywhere except for when lights are on u need a dehumidifier to lower it, you can have as much air flow as you want but if intake is high rh then you need to remove it!

[UrbZ]

BlueBudz is correct on the fact that circulation will not drop humidity alone.

But the more circulation the less chance that mold spores can land and reproduce when there is high humidity. I run up to 55-60% in my tent and Im in week 4 of flower, way too high RH. But I have 3 fans going in each 4x4 just for that reason. The air in my tent never gets stagnent. But I also keep one 6 inch in and 6 inch out running in both tents all lights out as well. So my two tents im running 10 fans all together when lights are off and RH is high.

But yes air exchange is just as important as circulation.

[BlueBudz]

Absolutely UrbZ, I just meant if your exhaust is in the same room as intake the humidity isn’t actually being removed by the air movement alone. It’s gotta go somewhere

[UrbZ]

I concur!

The main goal is airflow, airflow.

[Cali]

Thanks for all your reply’s guys really appreciate it. I’ve kept my exhaust fan on for the last couple nights and the highest my humidity has gone up to is 45 which if I’m not mistaken it’s ideal..

[BlueBudz]

There ya go! I just keep mine on for that reason too

[Cali]

UrbZ thanks for the info now I know to go bigger I almost bought a small one but luckily I was able to correct the problem without one. If ever I do need one I’ll go big..

[UrbZ]

No problem at all.

You can get a decent one for around 100$, I know it seems like a big investment at once but you nor your flowers will regret it.