Why is Humidity in my Tent so High?

Okay, I just installed a 6" Vortex @ 300cfm with carbon filter and now have an aircooled MH Hood.

But now for some reason, the humidity stays at a constant 60 even with the dehumidifier running all night long.

What could be the cause? What should I do to get the humidity more under control without having the dehumidifier on 24/7. I thought adding the exhaust would help out with the humidity.


Should I keep the tent fully closed? Right now I have a few holes in the tent open to let out some heat and help bring in fresh air. but the main tent doors are always closed.

BTW ( 6x4x7 tent, soil medium, inside tent temp. 73. , outside tent humidity 65 )



thanks in advance for any help.

Do you have any oscillating fans inside your tent running 24/7? Mine was going up to 70% when the ventilation would turn off so I left a single fan inside running 24/7 and the highest it's been is 55% since then.

Good luck

If you are blowing 300 cfm through your tent that means your tent is going to have whatever humidity the outer room is. If the outer room isn't sealed then your dehumidifier is going to trying to dehumidify your entire house which it just can't keep up with.

Is your res sealed? Any open water sources lying around? I would make sure to clean all that up and to seal the room. What is the outdoor humidity?

I would remove the dehumidifier from the tent too keep the temps down and control the humidity in that room, close it off. You may need a larger dehumidifier.

Gastanker said:

If you are blowing 300 cfm through your tent that means your tent is going to have whatever humidity the outer room is. If the outer room isn't sealed then your dehumidifier is going to trying to dehumidify your entire house which it just can't keep up with.

Is your res sealed? Any open water sources lying around? I would make sure to clean all that up and to seal the room. What is the outdoor humidity?

Click to expand...

I have two oscillating fans inside the tent, one that runs 24/7.

The humidity outside the house is high, coastal area.

I have no open liquids in the room.


I think air from outside is getting through. I will seal windows with wall insualtion. I will also try sealing the door and make it aortight in that room. but then i will worry about fresh air intake...

one solved problem always causes another...