Humidity too high?

Blahblah4242

Active Member
Hi all,

I'm on my first grow in a new stealth cabinet and need some advise. I'm probably on my 10th or so grow overall - lost count.
My new cab is 2x2x4 running a 150w hps. I don't have any ventilation and would like to keep it that way if possible. (for stealth sake. - Ducting coming from a cabinet always strikes me as odd.)

Anyway, temps are running around 70F with lights off (Min 66.6F) and around 80F with lights on (Max 81.9F)

Humidity is Min 43% and Max 70%. As the temps reach 80F or so the humidity rises up the max.

I am on day 30 of flowering and was wondering if you all thought the rH was too high to finish up flowering. I've heard that low rH is better during the last weeks of flowering?

Any thoughts on if the rH is too high or ideas on how to lower it without additional duct work would be greatly appreciated!

Thanks!
Blah.:-)
 

runsfromdacops

Well-Known Member
thats waht i was going to say. go with a Dehumidifier if you have the room for one other then that it would have to be fans and vents.
 

Allgrownup

Active Member
ebay is your friend. I've got a dehumidifier with a pump so what gets extracted gets fed back to the reservoir. cuz i'm a lazy stoner. For a small cab like that, just put some muffin fans in the back. You need to pull some fresh air through that box. maybe place a muffin fan at the base to draw in cooler air and vent it through a aquarium carbon filter at top. trial and error always worked for me.
 

Willy Nilly

Active Member
LOL. WEED needs air! Period. Get a fan. 30 days of flower? well its not too late, that high humidity will mess something up at some point. it needs to be at 50% during the night as a high (during flower)... it will fall during lights on. Humidity drops as temps go up. Humidty should NOT go over 65% during flower and should be lower than that as you move later into flower. No fans, and high humidity? sounds like the perfect recipe for Mites and powdery mildew. i'd do something about it if I were you. You won' be a very happy camper, if at day 45 you see little white spots and spider webs.
 

Blahblah4242

Active Member
LOL. WEED needs air! Period. Get a fan. 30 days of flower? well its not too late, that high humidity will mess something up at some point. it needs to be at 50% during the night as a high (during flower)... it will fall during lights on. Humidity drops as temps go up. Humidty should NOT go over 65% during flower and should be lower than that as you move later into flower. No fans, and high humidity? sounds like the perfect recipe for Mites and powdery mildew. i'd do something about it if I were you. You won' be a very happy camper, if at day 45 you see little white spots and spider webs.

Oh, I have fans, two in fact. Just nothing pushing air out or into the cab.

The humidity is rising with lights on, not falling.

During lights off the rH gets as low as 43%...they have been off for 5 hours now and are currently at 49%.
 

OregonMeds

Well-Known Member
Your plants need fresh air, you cannot grow successfully in a sealed cabinet even if you use a dehumidifier.

How sure are you on those temperatures btw? A sealed cab that size with a 150hps should hit over 100f within a half hour to an hour and cook your plants easily. Are you watching the temps with the door open?
 

Blahblah4242

Active Member
Your plants need fresh air, you cannot grow successfully in a sealed cabinet even if you use a dehumidifier.

How sure are you on those temperatures btw? A sealed cab that size with a 150hps should hit over 100f within a half hour to an hour and cook your plants easily. Are you watching the temps with the door open?

Nah, I have a remote thermometer/Hygrometer.

I'm gonna figure out how to get an exahaust in their after this grow. It seems to be the consensus that having some fresh air would be best. This is my first HPS grow - everything prior being under 125w CFLx1 + 43w CFLx3.

I still consider myself to be a noob so a really appreciate everyone's advice!

Thanks,
Blah.

P.S. I think you're right about the temps in a sealed cabinet. Mine's not 100% sealed..it's built under my stairs so it has a bit more room behind the back wall of mylar that probably allows some of the heat to disapate.
 
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