thank you, @blackthumbbetty thats a good one.
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I’ve still yet to figure out vpd it confuses me so if I’m at beginning of week 6 at 78-79°f CONSTANT and 40-45% rh CONSTANT where do I fall on this chart I feel I need my rh below 45% all the way through flower due to previous pm issues
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If you’re really trying to hit that good VPD at week 6 in flower, with temps at 77-79F, you want your humidity between 50-53%. A couple weeks before harvest, you can let that drop down, so when your buds start to ripen, those trichs and terps will really pop in the lower humidity.
For mildew issues, have you checked out your ventilation and airflow?
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Yes I have I increased both airflow inside and intake and exhaust as well as a uvc hepa and so far so good in the flower tent I will increase to 50% and see how she goes I have just been very wary and super tentative this run so far its like day and night the density already is 10 fold as well as Terps and trichs it’s insane what a 5-7°f temp drop will do
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Also planning on putting a new 400cfm exhaust fan in my veg tent and adding the 2 booster fans I’ve been using inline with the flower tent fan
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Highly informative thread.
I personally grow vertically as well as horizontally.
In my horizontal rooms I have no problem dialing in vpd.
However in my vertical rooms, vpd is an issue for me.
My vert rooms run cooler at canopy and warmer at leaf temp (confirmed by infrared thermostat).
This in turn requires a drastic reduction of room Temps to balance out the increase at leaf Temps, in order to achieve my desired additional co2 temperatures.
These fall in the low 80’s in my experience.
Any of you players had any experience dialing in vpd in a vertical grow?
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yeah, the vertical rooms i’ve worked in required alot of AC, because they were all HID’s and the infrared raises the leaf temps, and everything is very crowded.
First time reading this thread, optimal is all relative, strain dependent , light dependent(to adjust for leaf temp), C02 dependent(higher temps in higher c02 environments)
And the VPD chart green area just shows optimal transpiration, sometimes having plants transpire to fast (in the green) is not optimal
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Rickles, you are spot on.
Running regular horizontal grow vpd parameters, blows in vert.
I have plenty ac, 10k hid’s, humidity, dehui, co2, basically all the factors to really throw a large spanner in vpd structure.
I’m in coco, and the wheels start to wobble when I start multi-feeding in mid flower. Indica dominant hybrids.
If you have any insights to offer, I am all ears. 
I have a formula i use that works bang on every time.
I dont know since their are so many variables (the medium, the nutrients, feeding frequency)
Dude. Throw a brother a bone.
- Coco/perlite on automated drip.
- First half of bloom at 2 waterings a day. Second half between 4 and 6 events.
- Gh nutes ( coco specific) at 750 ppm to 850ppm at full speed) ph 5.9-6.2.
You know i would if i knew hoe brother, sounds like you know
what your doing. How are they stumbling? just slow growth?
Looks like overfert. And P lockout.
Too busy trying to dial vpd in…
Overwatering perhaps?
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I have none of this in my horizontal rooms, so I’m feeling the vertical blues. Lol.
hook us up with a pic
Pre flower
Oookay. That’s very impressive.
I’m posting some half assed shots of one of my current grows.
Minamal issues, slightly N heavy, 4 weeks out.
The minute I step this up to multiple feedings the wheels start to wobble.
Um. How do I post pics?
the ^ arrow above where you type
I don’t have that option in my toolbar.
Too new here?