Low humidity what to do

Did you try turning down exhaust fan if you have a speed control might help with maintaining humidity if you can ?

Thanks for the input! My grow box is getto. It has a few gaps here and there and made out of wood. I have passive air intake and passive exhaust. There are fans hooked up to the air intake and exhaust but they only come on when it is too hot or to cool it down when the lights go out. The air intake is at the bottom and the exhaust is on top. I have my setup in basement so it is cool down there and I run a ceramic heater to keep my temps up which I think it is drying things out. I do have a fan on inside the grow box to circulate air inside and plus the humidifier going to move air as well.

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Lmao my box is gettho also made it from a palett some left of 2x3s and 2 mil plastic lined it with a old emergency blanket on back wall and metal tape on other 3 lol it works but I do have power exhaust and intakes I also need to run a heater in my box I have it my basement
Maybe try putting a bucket with bit of water with a rag sticking out acting like a wick a place it near one of your fans in box ?

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I put a bowl of water with towel plus humidifier. Worked on the door which was warped. Add some 2x4s and some foam seal for around the edges. It fits some much better there is no light coming out around the door. So I figure no more drafts. Just finished so we will see what happens.


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Hey @Smokin_ernie
I don’t know if this would help but I’m maintaining around 50% humidity on average right now my basement is 65 f because I heat the whole thing but I have my tent enclosed in basically another tent I made out of plastic I lined the ceiling and the three walls I also sectioned off my basement with a plastic wall and installed a zipper door :door: to access grow room I did this mostly for smell but since its cold in ny this time of year I’ve been running my exhaust fan and dumping air from tent into grow room this way it recycles the air I also run my intake fan to draw air back into tent I notice that the room stays warmer and higher humidity levels then my main basement? Just a thought plastic is fairly cheap may help you maintain humidity just need to watch temp I run leds so not much of a issue for me with temps :thinking:


Yes it does help. I have been thinking of lining the whole box in plastic to block the small leaks. As for running the exhaust fan into the box is a great idea. I will have to look into that. As for right now I made a small green house out of some wire and zip lock bags. I hope it warms up nice. I don’t think my ladies are growing. It has only been day5 since they popped out of the soil. They only have a set of round leaves and a set of jagged leaves. I would think that they would have more leaves starting at least.

@Smokin_ernie relax bud it early stages for them I’m sure it just rooting even though you can’t see growth above soil I doesn’t mean anything
When they are that young they will not show growth above soil for a few days while they grow a nice root system under the soil :+1::v:️️:wink:
Just try to provide the best environment you can and don’t give them any nutts yet

Pics help so if you can post one or two of the young girl

I know I need to relax. Thanks for setting me straight. haha I will post pic after work.

Nice we all get excited lol
I was so nervous about over feeding mine that I under feed them to Nutt Def
had to bring them back but all good

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Here they are.

Just checked them and humidity was 46%. Sealed all doors and any where that let out light.

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I used this method. The first bowl of water with a towel raised my humidity by 13%. I added another one(bowl + towel) last night before lights out in an attempt to get at least another 10%. Working great. Thanks for the advice!

Glad I was able to help…


Looking good :blush:

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@Donaldj , can you raise the room 5 degree’s s safely ?? itll make your RH start to climb fast .
Hammer .

Sorry buddy I have my own grow journal going on and raising my unheated crawlspace’s temp by 5f would put it at 53f tonight lol

The towel in a bowl of water worked great. I made a small tower out of wire so I could draped the towel over it. The biggest thing is I sealed up the doors with weather stripping and some duck tape for the spots light was showing. With the humidifier it should get a bit better.

Thanks everyone for the input!

Cannabis grows best between 40 - 60% RH, hope this helps! :thumbsup:


Right now I am at 42% and that is just the towel. My humidifier doesn’t work with a timer. I tried it and it will shut it off but when timer goes on it doesn’t turn on humidifier. So I have to mess with that after work when I have a few hours to mess around with it.

I get you I’m using an old-school one that I used in like the eighties no digital just simple

…is it the digital kind where you can just set the humidity ? I saw a nice one someone put a link up the other day on Amazon around fifty bucks, a set-it-and-forget-it type