HOW IMPORTANT IS HUMIDITY??

tripleD

Well-Known Member
I'm having a problem maintaining stable humidity in my grow area & I was just wandering how important this is? The humidity drops down to 20% on days like today & I'm totally maxed out on my breaker so I can't plug in a humidifier. I'm thinking about maybe putting some 5gal buckets in there....Any suggestions??
 

guardogz

Member
i dont do any humidity control. can be in 20's like yours. so in the winter it s too low for veg and in summer too high for flowering. i get some edge of leaf curl(upwards) when the fan blows w low rh and temp. perhaps a bit of wind chill. easy fix for that. in summer keep the fans running and the air circulating. i think low rh keeps bugs down and eliminates any mold issues. my 2c
 

TheFuture

Well-Known Member
RH is important. At 20% the plant is transpiring too much water. You want to try and get it around 40%. I recommend using some moistened coco coir. I add a little Cease to the water so there is no chance of mold or mildew blooms, and the amount of moisture that wicks off to contribute to humidity can be enough to need a fan on Low. Im using a 2' x 3' under-bed rubbermaid storage container (with the wheels) and about 1.5" of moistened coir. Minimal cost for desired effect. This is going into a 3' x 9' space.

Also, never hurts to turn your lights down or off and mist your plants with water+insecticidal soap or foliar feed 2-3x a week to help nutrient uptake as well as increasing RH at the leaf surface.
 

curious2garden

Well-Known Mod
Staff member
I'm having a problem maintaining stable humidity in my grow area & I was just wandering how important this is? The humidity drops down to 20% on days like today & I'm totally maxed out on my breaker so I can't plug in a humidifier. I'm thinking about maybe putting some 5gal buckets in there....Any suggestions??
I grow in the Mojave Desert. My humidity runs in the 10% range give or take. Humidity has not been an issue for me.

Two nights ago in the flower room
Kk-jan20161.jpg Kk-jan20162.jpg Kk-jan20163.jpg
 

ArcticOrange

Well-Known Member

curious2garden

Well-Known Mod
Staff member
That leaf edge curl is a sign of over transpiration. Obviously the crop is doing fine but it could also vlearly benefit from slightly higher rh.
VPD is a secondary issue. It isn't that important a battle to fight compared to getting the plant through it's life cycle without killing it. Later you seal your room and worry about CO2 and running at max efficiency. Otherwise it matters minimally, it has not hurt my yield nor my quality and I run a canopy all summer long at 105 ;D I lose 10% of my weight, still cheaper than air conditioning. I've just begun considering when to seal my rooms.
 

since1991

Well-Known Member
Once you got good strains and a really decent real growroom....controlling the humidity in relationship to the variety being grown can bring out the best the genetics your working with. Humidity and the ability to control it very precisely means alot to my garden.
 

DemonTrich

Well-Known Member
Please see the VDP chart for optimal rh grow conditions.

I've found no ammount of 5 gal buckets with water won't do any good. Or at least is the 3 seperated spots I've grown in over 4 years.

Now a bucket of very hot water will raise rh a bit, but then will diminish after the water cools.
 

since1991

Well-Known Member
Foggers work. Buckets of water or even most cheap commercial humidifiers wont cut it. Intake air if your running an open vented room. But that largely depends on outside weather conditions. Those fancy mister fans that sit over a 5 gallon Depot bucket look cool. Anyone tried those increase humidity? I know one thing....keeping rh and vpd in the sweet spot with the rite temps and THEN add Co2.....wow. Plants explode with vigorous growth. Especially in veg and the first 5 seeks of flower. Bud set is way faster than "keep rh at 50% at all times" bullshit.
 
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