Would it work/be enough time, to drop to 40% or so on the last week, or two weeks ?
Couldn't hurt IMO.
I start the low RH at week 1 of bloom and by the time I see cotton balls, I'm also wanting to see trichs on leaves.
Damnit Bandit!
Now you have me rethinking everything! Everything has to be dead nuts Perfect for me to get close to Redbull can sized buds. I definitely have absolutely no proof for the reasons why I do what I do besides the fact that it’s the way I learned. Now I’m insanely intrigued!
I know for a fact my equipment and controller will keep my little room whatever I tell it to. So since I’m a few days from FLIP I am going to message you about more details if that’s ok?
Peace
Message received!
So I learned about basic room control and air exchange from old how to grow books and manuals. I think the basic outline was room temps at 75, RH at 50%, and complete air exchange every 5 minutes.
It worked well but not good enough due to the climate I deal with and that's what got me going online and looking at others' grows to better dial in my own grow.
Two things began to stand out from what I saw with growers in Hawaii and Colorado. Hawaiian outdoor grows were super lush and indoor Colorado mountain grows were super frosty.
From there I took the basics of cannabis in that it's really not that special or unique in the fact that it's just a Spring germinating, Summer growing, Fall blooming annual that goes dormant in Winter. Only real unique thing is that it's phototropic and has an incredible zeal to reproduce but at the end of the day it's basic annual gardening like growing pumpkins or something like that.
So I figure take that info on the plant, give it a room that simulates a Hawaiian Summer for veg and a Colorado Rockies Fall for bloom, I'm gonna get very close to what I'm looking for at harvest.
To do that meant going outside the lines of what I thought was mandatory in the old 75*F-50% RH I read in books.
For me, 85*F and 40% was the sweet spot with a gradual decline in temps each week during bloom until ripening. The cooler and drier air toward the end, the better so at harvest I'm wanting low 70s and low 40sRH, high 30sRH during lights on, low to mid 60s temps at lights out.
To achieve that in this location is not ez at all. It's a balancing act bringing in outside air, changing it's temp, and reducing it's RH.
Combine that with the 400+ BTUs of heat produced by lights and the water transpiration of the plants raising RH it becomes something like a circus or ballet.
Ideally I need a cold source of fresh or CO2 laden air, various sized fans blowing at various CFMs from floor to ceiling, speed control on intake and exhaust, and controllers and monitors to keep it all in balance trying to create Hawaiian and Coloradan environment.
Every day brings a new variable especially being outside air dependent. Combine that with the plants size and number of them, every day the room has environmental swings but kept within boundaries set by me and the devices.
Here's a walk thru on my environment right now as it's in Winter grow op mode.
This week is cold and rainy outside. Mid 40s and 80% RH
Here's my fresh air intake. An ACI hepa filter box with a coaxial fan on a speed controller and set using a day night thermostat.
Air that cold only needs to trickle into the room so no need for a powerful inline here. 20-40 CFM is more than enough on the cold intake
With the filter box and CFM control, that 44*F 80% RH outside air is transformed to 69*F and 48% RH.
I like to call this free air conditioning.
That intake fan is on a day night thermostat so if this air gets too cold it will shut down the intake and let the room warm up
Once the cold air is inside it's mixed with heat from the lights, humidity from the plants, and ambient available CO2 provided by people and pets living in this home.
There's a total of five 6" fans, one 8" inline on the lights, dual exhaust at 6" and 4", one 16" wall mount fan, and one 22" ceiling fan mixing up the air in this 10'x10' room.
After the blend I'm right in the wheelhouse of where I want to be at week 4 of flower but I wouldn't mind seeing the RH maybe 3 to 5 points lower.
As these plants begin to slow on water uptake that RH will dip so I'm not gonna fuss with it and try to perfect it.
If it was high 50s or above I'd increase exhaust CFM to tamp it down.
After the air is blended there's inner variables at play. Temps and RH, like lighting, has sweet spots within the room and I can tell this by taking temps of the plants, both off leaves and flowers using a laser thermometer and temps will range anywhere from mid 70s to low 80s.
Next, I take those numbers and compare it to what I see the plants doing and that's how I identify the sweet spots in the garden footprint and if my settings are in a good range.
I'm looking for one thing here and that's early frost. If I see fan leaves with resin on them it's telling me my room is performing even with variable flex in environment and at the end if I keep these plants lush and healthy, is gonna be some fine smoke.
I'm getting that so I'm feeling groovy about where this grow is going for me
At the end if these plants come anywehre close to specimens like these I'm gonna be very happy. I'll have the potency I'm wanting and a more than acceptable yield from these OG Kush variants and a really nice haul from the larger haze plants in the crop
It was nubs on nubs and holes on holes. So I was playing with it wondering what I did and then it all hit and I re-engineered the whole thing. Y'all are gonna trip!
