relative humidity

[emmy75]

im wondering what level of humidity is good for organic grows. i live in a very dry and arid area. since the end of summer the daily temps have come down to around 80. my levels of humidity range from 13-35 percent. i also run a 400 watt bulb which creates even more heat. so to rectify this i turn on my ac to about 60 degrees. of course this makes the air even drier. ive read many things about humidity levels. one is that the drier the air the more resin there is. on the other hand humidity should be around 50-60%. my plant is suffering a little from heat stress and im thinking lack of humidity, i was told. the heat i can take care of with the ac but what can i do, inexpensively, to increase humidity since my levels seem too low? thanks boys.

 

[Skunkenstein]

Seen Far Worse..

Seen Far Worse..

From those pics,,the plants don't seem to be in much danger..Really.You could add a humidifier..but it would probably cause mold and Yucky things to grow somewhere in the Environment.You could also place a bowl or bucket of water nearby..The best alternative would be a vented light fixture.You could and should also be bringing in fresh air/and exhausting, from a cooler area.Just by having a fresh air intake and exhaust will make a world of difference.I've seen room's Ripping hot with NO fresh air whatsoever..and they wonder why their plants are 7ft tall with miniscule buds.Environmental control is the absolute key to healthy plants...Good Luck.

 

[clowntown]

Get a humidifier! They're fairly inexpensive.

If you were a DIY'er, you could buy an ultrasonic fogger and a small fan to create your own DIY humidifier.

 

[green_grow]

my plants seem to appreciate being sprayed twice daily with plain water. might be worth a try, particularly in low humidity like you have . good luck.

 

[judas cohen]

I live in the desert. A small swamp cooler (evaporative-type) lowers temps and increases humidity. Much cheaper to run electricity wise than a compressor type A/C. Works for me, might work for you.

 

[clowntown]

my plants seem to appreciate being sprayed twice daily with plain water. might be worth a try, particularly in low humidity like you have . good luck.

I think this goes without saying, but don't do it when the lights are on.

Actually, I haven't had any problems under small wattage CFLs for my seedlings but under HIDs it's definitely a no-no.

 

[emmy75]

thanks for the info. i think ill look into the swamp cooler. i hate walking into a 50 degree house just so i can cool down my plants. but what should ideal humidity levels be for mj? is 50-60% right? and is it throughout both veg and flower or does flower prefer a differnt level of humidity? thanks

 

[vonforne]

Vegging...40 to 60 %. Flowering 30 to 45%. And remember during the lights off time in flowering the humidity will shoot up about 20% so you will need something to keep it down. You live in a dry area so just use the air exchange method to keep it down.

 

[judas cohen]

There's "ideal" and there's "what works". Bear in mind that reefer grows outdoors in the desert just fine. Max Temp I experienced this summer was 123F and 8%RH.(on my patio in the shade.) Not ideal, but it worked. For sure, 80F and 50% RH is better.

Portable evaporative coolers are available at Walmart for under $100. Small portable humidifiers for people with breathing problems are $20. If you have a small grow space or closet, either will work.

(I prefer the swamp cooler. If designed into your grow cab, it can be used for cooling, venting, and adding humidity. It is relatively cheap to run. It also has a 3 speed fan that can be used to pressurize your cabinet and allow a passive exhaust. If you turn the water pump switch to the "off" position, it can be used as a "fan only" in cool weather. A "toilet type" float switch and water line can be easily installed if adding water by hand every 24 hours is undesirable.)

The smaller the volume of the grow area, the easier it is to control the environment. My 4'x2'x4' flower cabinet (250hps+250mh) is in a small room. The evap cooler is ducted to blow into the bottom of the cab and passively vent out the top into the room. In extreme summer heat, a refrigerated window type A/C is available to cool the room, but is rarely used since I run my lights at night.

Moldy colas during late flower is my biggest concern regarding Relative Humidity. Usually not a problem in the desert. The RH numbers stated in this thread agree with most of what I've read regarding "ideal". My personal experience leads me to be more relaxed about what works; but I have never conducted scientific experiments regarding humidity.

If I recall correctly, Krusty and his Freedom Buckets (best marijuana yields I'm aware of) very strongly states that humidity should be 80% to avoid stressing plants. His grow technique utilizes high pressure pumps to spray water throughout the grow.

There are many ways to grow. I recommend each person use the way that feels best to the individual. Raisin' reefer should be fun, IMO. :smile:

 

[emmy75]

theres nothing more that i want than to be a perfectionist when growing mj. it really bugs me that my plant suffers heat stress when my lamp is 15' inches from the top of my plant. but when its 26' everything looks good and theres no stress. to boot my plants still have new growth everyday. so personal experience by far is the best. what works for one person or lots of people may not work for me. so yes i think the best advice for noobies is if its not broke dont fix it. enugh said.

 

[The Strain Man]

three one gallon jugs of water might work if your room is not too big.

 

[emmy75]

ive been spraying my plants with just plain water to assist in humidity. i was thinking of gettin a humidifier though. if i get a humidifier or swamp cooler to bring the room's humididty up to 40 can i run my lights while the humidifier is on? i am using a 400 watt lamp. of course ill only be using the humdifier during veg of which i have another month to go.

 

[Dignan]

I have the same conditions. I've never been so bothered that I did anything other than more frequent misting, but if you have a square foot of space to spare, you can set a bucket of water in the room with an airstone in the bottom... the constant bubble-poppin' fun will raise the humidity, depending on the size of the area and the air exchange rate.

Dignan

 

[Fonzie]

I also have the low RH challange and the easiest and most fun way to increase RH is increase plant size and quanatity.

Average RH here is maybe 20% in the house - 30-35% around the plants - sometimes it seems hard on really young plants, but after adjustment,,, I think it's not all that bad. We have the advantage of being able to grow some strains that might mold or rot in a higher humidity enviroment.