What's new
By:
GrowWeedEasy.com
You're browsing as a guest. Sign up to join the conversation, share your grows, and get help from thousands of fellow growers — it's free and takes less than a minute.

humidity in grow tent

M

marpolo

New member
in the flowering cycle no problems with humidity during day cycle, stays around 40-45 %, night when the lights go off it rises to 55- 64 %. i have two small dehumidifiers in my tent 4x4x80. why do humidity levels go up when lights are out? another 3 weeks I'll need to be between 35- 40 % for end of flowering cycle. bigger dehumidifier? no exhaust set up, would that help? only have a 300 w LED and a 150 W HPS in tent. thanks for any help in this matter...
 
The humidity goes up because the temperature goes down during the dark cycle. Yes an exhaust set up will help.
 
Both...pull cool air in and push the air out through a vent to outside or through a carbon filter for the smell
 
Warm air will hold more moisture than cooler air.

Lets say that a room that is 80 degrees F, can hold 2 quarts of water

If is has 1 quart of water evaporated in the room, it is at 50% of the water it can hold, so there is 50% humidity.

When that same room full of air cools to 65 degrees F, the room can only hold 1 1/2 quarts of water evaporated into the air.

It still has 1 quart of water evaporated into the air, but that one quart now represents 66% of the maximum the air can hold and therefore reads 66% humidity.

Your humidity numbers are all good, by the way.
 
thanks again man! my first grow , looking forward to the end of this cycle. just planted two auto seeds yesterday..looking for a shorter period of grow time. they seem to be a totally different
style when it comes to them. any pointers on those . appreciated as well!!
 
my VPD according to chart is around 1.3. that a good place to be? that's an average i range from 40 % RH - 64% RH . temps stay between 72 degrees - 80. days closer to 40 nights closer to 60 % RH. and thanks for the auto info also. can and do you recommend using lights or outside for the auto flowers. or a little of both??
 
i have six seeds ,I'll try both ways and see which one comes out best. I can get 6-7 hours of direct sunlight every day. will be fun to watch the difference. thanks again..
 
Lol... I thought VPD was a STD.... When you start your autos... Keep them under 24 hour light for about the first month... I start my seeds in Rapid Rooters after they pop, then I keep them warm in a humidity dome until I see the sprout starting then I throw them under my cheap ass $15 Amazon special 50w LED light that is a circular disk shape, I wrap the light with a towel... Couple of chip clips to keep the towel closed.. once I see some root start to show through the rapid rooters, I sink them into my soil mix in these cheap plastic pots I got from the dollar store. Once they get going I then put them into their final pot. But I really think that the 24 hour light at first really jump starts them. And I definitely put my autos outside whenever I can.
 
The thing for me is that I am not committing to the perfect environment.
I consider myself a average hobby grower at .66 grams per watt on my light.
If I am going to spend a bunch of money to control more than that, I want go get that back in my harvest, or I won't do it.
As it is I need dehumidifier in flower, but that is just to survive in the summer, and I will not use it when I don't need to for mold protection.
I see crazy claims on this site of 1.25 grams per watt but I don't believe them, so I just grow along at my .66 and wait for something cost effective that will be the next big deal.
I started out studying everything I could get my hands on, and learning the science. All I found was false claims so now I grow, smoke, repeat.
I do enjoy learning what the science guys are studying currently, but my belief is that I don't think it makes a lot of difference.
 
You must log in or register to reply here.
Back
Top