how do i lower humidity

Well you should always have fresh air coming into your grow space. If your source air is highly humid then I would suggest getting a dehumidifier. All those homebrew techniques for lowering humidity pale in comparison to a actual dehumidifier.
 
How high is your humidity? And are you in a tent, a room, a basement?

If the humidity is high and you can't get it down, you will need to get a dehumidifier or else potentially lose your crop to mold.
 
DankkAbuser said:
Wat is rh??
Wat do u mean too high??
Click to expand...

RH, is the measurement of humidity (the air-water mixture) relative to the temperature & pressure.
Dr. Jekyll

Your thread title says "how do I lower humidity" thus it's only natural that we would assume your humidity is too high.
Hence the ask is how high is your humidity, in terms of % RH?
Why do you think your humidity is too high, do you have droplets of condensation dripping off your walls & plants?
Mr. Hyde
 
There must be some good research on mj and humidity levels that I haven't seen because so many people are concerned about it and I don't pay any attention until it gets too high and increases risk of mold.

Can somebody clue me in to the difference in yield that can be expected between a veg at 30% and one at 60%, for example. I'm routinely at 20% rh and have healthy grows.
 
oregongrowpros said:
RH = Relative Humidity http://en.wikipedia.org/wiki/Relative_humidity

Cannabis ideal environment in my opinion is >>

VEG 50-70% but don't go to high, to prevent mold
FLOWER 20-40%
Click to expand...

Gads, not again... I flower at 70+% RH, with excellent results. Anyone who says to bring RH down in bloom at any time other than the very last week (if even then) is simply quoting outdated information. Low RH won't kill your plants, but it certainly will cost you yield- especially if you supplement CO².

Beyond that, there are plenty of fungal and other pests that either don't mind dry conditions- or actively prefer them; Colorado Powdery Mildew is one prime example- and spidermites are another.
 

Attachments

  • 20140123_215535.jpg
    20140123_215535.jpg
    106.3 KB · Views: 10
Bugeye said:
There must be some good research on mj and humidity levels that I haven't seen because so many people are concerned about it and I don't pay any attention until it gets too high and increases risk of mold.

Can somebody clue me in to the difference in yield that can be expected between a veg at 30% and one at 60%, for example. I'm routinely at 20% rh and have healthy grows.
Click to expand...
I agree, some think it's an important factor, personally we don't worry about it unless it's extreme high/low
Dr. Jekyll

The RH of our home is typically 60% but under the lights it's about 30%
We tried before to increase the RH but it was really just a wasted effort
Mr. Hyde
 
Bugeye said:
There must be some good research on mj and humidity levels that I haven't seen because so many people are concerned about it and I don't pay any attention until it gets too high and increases risk of mold.

Can somebody clue me in to the difference in yield that can be expected between a veg at 30% and one at 60%, for example. I'm routinely at 20% rh and have healthy grows.
Click to expand...

VPD= Vapor Pressure Differential. It's the idea that when plants aren't struggling against wilting (or vapor saturation), they can spend more energy actually growing.

Thumbnail chart; 'keep it in the green'
Example; my own room runs at 83F and 78% RH. Insane, right?
Chart says.... perfect! And so do my plants, who always get the final say.

View attachment 2974877
 
Thanks for the info tystikk! I am curious how mj specifically would chart, the same or different? Seems like mj has the ability to push out resin to combat low humidity so maybe it has a broader range? Most of the time my grows aren't even on your chart! But even in dry Colorado we do get high humidity for short periods too.

I can see how rh is probably very important to commercial growers, just not sure how important it is to newbies...I can think of a lot of stuff I'd recommend they purchase before humidifiers or dehumidifiers. I am certainly curious to learn more about this though.
 
I dont have ahydrometer
so i dont know ifitts too high
my leaves are droping
so i guess o figured it was humidity
but after reading up and looking over all ur guys replies
it looks like its not humidity
since u. guys say it can go upto 70% without harming my plant
i dont think its that high tho
im almost possitive ive just been overwatering my plant..

but ill be buyin a small dehumidifier and a humidity meter in a week or so
and then really see ita level
 
You must log in or register to reply here.
Back
Top