humidity control

trance

Active Member
hi all,

I have just built a grow box 36"x18"x48". My problem is with Humidity. When the lights and fans are off the humidity is fine, around 55-65%. When I have run my box up for testing (not planted anything yet!) the humidity falls to 20-25%. I have my temps down to around 25-27 degrees C. The box is in my shed so I am controlling surrounding temps as well, keeping them around 20 degrees C when my lights are out. Problem again is with the shed heater on the humidity is down to 30% at night while temp is only 20 degrees C. I am aware of humidifiers and what not and have even tried a mini fogger (in the shed not in my box) inline with the intake fans to try and resolve the issue that way. There is no space inside the box for a humidifier so its very difficult, even if I buy a small one then its has to be filled every 10 hours or so, just can't be around that much to do that!.

When I put some plants inside the box can I expect the temps to rise more than with testing and will the humidity also increase with the plants being there?. I am not really wanting to spend mega money on a humidifier in my shed when the inside box humidity will not rise enough. Has anyone any suggestions please, I ned to start growing and the testing ain't going to plan!!


Cheers

Gregg
 

DaBeatGoezOn

Well-Known Member
Boil some water and pour it into bowls and place the bowls around the grow area close to the plants. If you can, put the water in a bucket and let it sit there. Mist the plants at night. Keep the plants close to each other.

Hope it helps:)


Cheers :)
 

trichome addict

Active Member
I wouldent worry to much about needing a humidfier,
as the amount of plant matter inside your box increases
you will find humidty increases too,but as long as your exauhst fan is good enough u should be ok
heat build up could aslo increase a bit as vegetive mass takes up airspace.
 

homegrown2009

Active Member
ummm. chill out, your fine too high is a lot more problematic.
as long as the humidty 50 to 60 fine when the lights your all good it doesnt matter if it drops at night it only when they lights are on when they getting fed and all the other stuff think of it like this when our lights goes of does your temp drop so if the temps fulcate like that so can the humidey
 

trance

Active Member
Had a look at the DIY hunidifier, looks simple enough. Thanks for that carbon. I think the issue is the surrounding area around my box. I have an inline exh fan onto a 400 watt HPS air refelctor , 2 mains axial exh fans and 2 mains intake fans. i think I need to bring some more outside air in. i am hoping this should bring humidity up and even some temps down. Means cutting holes in the side of the shed though! :neutral:




and if you have the patience and money&stuff for it you can build a humidifier here you go: http://www.instructables.com/id/Evaporative-Humidifier/
 

CarbonBubblegum

Active Member
never mind that, it´s not an actual (i think) but should work nontheless.

If you cut them neatly it wont matter much, You can get these ducting square things that make the hole look really nice, they are used with kitchen/bathroom outlets i think.
Do you already route the air inside the shed into your grow box?
 

CarbonBubblegum

Active Member
also, our loved plant lets out more moisture as it gets older, so if the plants are really young you should expect a rise in humidity as you go along, hope to be of some help :mrgreen:
 

trance

Active Member
Thanks for the info carbon. I exh into the hut with the 2 exh axial fans, but the inline fan goes outside. Gets cold at night though so can be difficult to control box temps. Its all trial and error, still in testing mode. I don't live in a warm climate so was surprised when the humidity was low.


also, our loved plant lets out more moisture as it gets older, so if the plants are really young you should expect a rise in humidity as you go along, hope to be of some help :mrgreen:
 

Jerry Garcia

Well-Known Member
The only time you want high(er) humidity is during seedling growth. During flower, you want the humidity low, as this helps reduce risk of bud rot and mold, as well as (potentially) increasing trichome production.

I had the same problem with my last grow. If you can get a humidity dome or place a clear plastic cup over the plants this will help.

Also, you can mist the plants 4-6 times a day to keep them and the top of the soil moist.

I don't think humidity has too big of impact though unless it is really far off (like 5% or 95%), and my experience says not to worry about it.
 

trance

Active Member
Thanks Jerry. I think I will just wing it and see how the plants get on with that humidity. Its a major hassle trying to raise the hunidity levels, and its going to involve spending more money!. If other people are growing it at those levels then thats good enough for me.

Cheers





The only time you want high(er) humidity is during seedling growth. During flower, you want the humidity low, as this helps reduce risk of bud rot and mold, as well as (potentially) increasing trichome production.

I had the same problem with my last grow. If you can get a humidity dome or place a clear plastic cup over the plants this will help.

Also, you can mist the plants 4-6 times a day to keep them and the top of the soil moist.

I don't think humidity has too big of impact though unless it is really far off (like 5% or 95%), and my experience says not to worry about it.
 

CarbonBubblegum

Active Member
i live in a cold climate too and have found out that in cold there is usually low humidity. It´s a health issue for people that want their skin to be pretty. They use lotion on cold days cause the humidity is low :) see.
In warm there´s much more humidity in the air cause of water evaporating, that is, if there is rain, plants also release a bit of humidity as far as I know.
I´ll go with Jerry´s approach, cheap & easy :)
 
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