Hot Diggity Sog - Chapter 5: The Big One

Hot Diggity Sog

Well-Known Member
I stay from 58-65% all the way through flower. 74-77f lights on and 67-70f lights off. All the time. No leeway for big unplanned swings cause that’s how you get dew which causes the fungus problems if paired with inadequate air circulation.
You and one other person have said exactly this. I'm gunna try my best to get nearer to these numbers. I'm at the mercy of my large basement and the outdoor weather. I've been running a heater at night and I can micro-manage the temps no problem. But the RH is difficult. I have a dehumidifier in my main basement area that I generally run 24/7. The only practical way I can elevate the RH is to shut off my basement dehumidifier (that only helps a little) and to control how often my exhaust fan runs. I built this room to be fairly air tight so when the exhaust runs (connected to a carbon filter obviously) it creates negative pressure and manages the odor perfectly. When the exhaust is off, it doesn't take long at all before you can smell it in the house. If I run my room exhaust 24/7, the RH and temps cannot be managed because my basement is very large.

I adjusted my heater before lights off and should be able to easily maintain 67 to 70 lights off and 74 to 77 lights on but RH is a big question mark until I do this for a day or two.
One thing I wanted to mention: When the canopy temp is 72 or below, there is very little smell. When its 74 or above, she throws out mad stank.
 

dstroy

Well-Known Member
You and one other person have said exactly this. I'm gunna try my best to get nearer to these numbers. I'm at the mercy of my large basement and the outdoor weather. I've been running a heater at night and I can micro-manage the temps no problem. But the RH is difficult. I have a dehumidifier in my main basement area that I generally run 24/7. The only practical way I can elevate the RH is to shut off my basement dehumidifier (that only helps a little) and to control how often my exhaust fan runs. I built this room to be fairly air tight so when the exhaust runs (connected to a carbon filter obviously) it creates negative pressure and manages the odor perfectly. When the exhaust is off, it doesn't take long at all before you can smell it in the house. If I run my room exhaust 24/7, the RH and temps cannot be managed because my basement is very large.

I adjusted my heater before lights off and should be able to easily maintain 67 to 70 lights off and 74 to 77 lights on but RH is a big question mark until I do this for a day or two.
One thing I wanted to mention: When the canopy temp is 72 or below, there is very little smell. When its 74 or above, she throws out mad stank.
You need a lung room. That’s how we do it and keep it there efficiently.
 

iPerculate

Well-Known Member
There are many sources that claim lower RH in mid-late flower causes more trichome production in reaction to the lower RH, (as long as you manage temps as well). Cannabis will grow well in any RH environment, as long as it is a relatively consistent environment. You can grow some pretty frosty buds in the desert. Lower temps and lower RH makes frosty dense buds, it happens in nature as the seasons change.

I start off at 60-65% at early veg, and taper down to 45-50% by the end of the grow. No big jumps, 2-3% at a time. I would keep yours right where it's at, it's lookin really frosty.
 

Hot Diggity Sog

Well-Known Member
There are many sources that claim lower RH in mid-late flower causes more trichome production in reaction to the lower RH, (as long as you manage temps as well). Cannabis will grow well in any RH environment, as long as it is a relatively consistent environment. You can grow some pretty frosty buds in the desert. Lower temps and lower RH makes frosty dense buds, it happens in nature as the seasons change.

I start off at 60-65 at early veg, and taper down to 45-50% by the end of the grow. No big jumps, 2-3% at a time. I would keep yours right where it's at, it's lookin really frosty.
Yeah...I've read that too. I've been especially paranoid this grow because I've never grown a big plant like this and she is friggin dense. I've removed 5 gallons of leaves and small branches from her inside 3 TIMES already just to thin her out a little in the middle. I've been really worried about mold and PM and so I've been OK running my RH levels lower than optimal. It doesnt matter how many fans I have blowing on her...the center just doesn't get any of it.
 

dstroy

Well-Known Member
Well there’s a whole big subject of controlled environment ag that you might find interesting hot. I did, it helped. A lot. There’s too much broscience bs in the cannabis world .

I’m a hard science first type of guy. That subject is a good read.
 

Hot Diggity Sog

Well-Known Member
Well there’s a whole big subject of controlled environment ag that you might find interesting hot. I did, it helped. A lot. There’s too much broscience bs in the cannabis world .

I’m a hard science first type of guy. That subject is a good read.
Yeah...I'm a science minded person as well and have no time or interest in bro-science either.

I appreciate you taking the time :)
 

led1k

Well-Known Member
Well there’s a whole big subject of controlled environment ag that you might find interesting hot. I did, it helped. A lot. There’s too much broscience bs in the cannabis world .

I’m a hard science first type of guy. That subject is a good read.
Any links you can provide? Google helps but I'm hoping for a more focused read.
 

dstroy

Well-Known Member
Any links you can provide? Google helps but I'm hoping for a more focused read.
Sure, I'm not sure what you're looking for specifically but there are a lot of articles on CEA. Even on google scholar. I can get to a lot more databases through a subscription service that I belong to. Fascinating stuff. CEA mass production level strategies, how they manage crops large scale. The knowledge those people have is invaluable to us. Nearly everything is directly applicable, and they grow crops for money so they're going to choose what works best to remain profitable.

http://cea.cals.cornell.edu/

http://cea.cals.cornell.edu/resourcesPublications/growersHandbooks/index.html

http://ceac.arizona.edu/

"light and crop management"
https://www.agweek.com/business/agriculture/4527042-cutting-edge-technology-will-change-farming

"light management"
https://www.amazon.com/Light-Management-Controlled-Environments-Roberto/dp/1544254490/ref=sr_1_1?ie=UTF8&qid=1544375971&sr=8-1&keywords=controlled+environment+agriculture

EDIT: let me know if I'm clogging up your thread hot.
 

EmeraldØsiris

Well-Known Member
Well, personally I think RH is relative to the strains origin. Indica/Kush come from the Kush mountains/Afghanistan/Marocco/Lebanon etc., meaning low RH especially towards end of summer, whereas sativa strains usually tend to thrive closer to the equator, example Thailand where RH remains very high year round. Maybe that's also why sativa's tend to take much longer to flower, where indicas have to rush into flower before cold winter climates come. High RH also aids in blocking essential Nutrients in flower period.
 

Hot Diggity Sog

Well-Known Member
I have a VPD chart hanging in my grow room and have ever since I became aware of it. Using it as a guide and while I'm not following it to a tee, it was very eye opening.
 
Top