VPD = PAIN

GemGrows24

Member
So Ive been making post one my OG Kush plant.This is my second attempt at growing cannabis. I couldn't figure out what I was doing wrong ultimately this has been resulting in slower growth and drying leaves. My first instinct was temp lighting and RH . But little did I know I hadn't been paying attention to my VPD like at all. Just keeping temp and humidity in general range but not thinking about the relationship the two have with the plants. After looking at data on my Vivosun Smart grow system. My past month my average VPD have been 1.4 . I believe this might have been the underlying cause of the symptoms my plants been showing. I've a just temp and humidity .77F and 70% RH with lights on . 72F and 68% RH lights off from now on. Hoping the plant shows signs of recovery here soon . Fyi this is week 2 of veg but has been popped since the 21st of Nov. OG Kush from RQSSnapchat-1201301081.jpgSnapchat-1847452194.jpgSnapchat-1201301081.jpg
 

Jjgrow420

Well-Known Member
Well thanks for the emojis but unless u have suggestions the questions aren't really helping. Regardless I'm telling u the soil it's most . It's a dry climate out here less I spray the top layer 3 times a day it's going to be dry for the first cm or two .
Plant looks like it has watering issues.
Medium looks bone dry...... That's where I started. Good luck with your grow. I'm sure it'll turn out great
 

GemGrows24

Member
Sorry to hear.
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Plant looks like it has watering issues.
Medium looks bone dry...... That's where I started. Good luck with your grow. I'm sure it'll turn out great
Ig this is just something I'll learn with experience. I'm just frustrated cause everyone has there own answer and everyone swears by there math I've heard underwatering and I've heard over watering. I've heard lighting issues and I've heard soil issues. Yet everything I've used and done has been backed with research and advise from these same resources. Parden my frustration . I posted about this yesterday with the same photos and I was told it was overwatering so I've been letting it dry out more. Now it's too dry.
 

Jjgrow420

Well-Known Member
Ig this is just something I'll learn with experience. I'm just frustrated cause everyone has there own answer and everyone swears by there math I've heard underwatering and I've heard over watering. I've heard lighting issues and I've heard soil issues. Yet everything I've used and done has been backed with research and advise from these same resources. Parden my frustration . I posted about this yesterday with the same photos and I was told it was overwatering so I've been letting it dry out more. Now it's too dry.
I know it can be a bit daunting at first. It will all boil down to exp. Once you get your watering 'groove' down it'll become easier. A small plant doesn't need the medium to be soaked, but it also can't have it to dry. Over watering and under watering can kinda look the same. Either way the plant isn't getting what it needs. Usually I'll pour a ring around the plant instead of saturating the entire pot until I see a couple roots poking out the bottom. Generally I prefer to up-pot just for this very reason. Start small and work up to your final container.
I don't like Fox farms but that's just me. I know some people do great with it and others have a lot of problems. Just search for fox farms in this forum and most of the posts are about issues.
 

Jjgrow420

Well-Known Member
What kind of lights are you using, distance, power level etc?
Any info will help make a better understanding of the root of this issue. (Pun intended)
 

driver77

Well-Known Member
Going by weight of bag might work better for you......feel how heavy it is dry so you know when to water. Another option would be go to a wick watering system......takes all the guess work out of the equation. Bottom watering/feeding may work better for you......I just fill a tray under plant as long as it absorbs it within an hour. Anything left I pour off.
I never let my FF get as dry as yours....it will easily get hydrophobic.
 

medidedicated

Well-Known Member
I dont follow vpd I want it dry as possible for avoiding mold. Close to 80F. If it makes you feel better the same thing happened to me with soil the few times I did it.

People told me dry and wet but too dry and my plant is dying, so I stayed on the wetter side. I kept a plant green til harvest once it just took way too long outdoors it was snowing so we chopped.

I said we it was a partnered grow and I wasnt always doing the watering. They were just watering when the top couple inches were dry. Then I grew a few soil grows myself and after about week 2 flower it just goes to shit but I still harvested.

I was top dressing fresh soil every 30 days it worked the first time then didnt make it to the next topping. Didnt do nothing when I topped it so I flushed which some do but some warn it just makes it worse. It did. So then I finished it off just doing recharge and plain waterings.

I tried adding maxibloom for a few waterings to no avail.. The recharge was the last attempt.

Microbes I heard needs like 6” of top soil as they live towards the bottom of the pot so small pots were tricky. Also microbes like hydrated soil. I did one plastic pot and one fabric. One was photoperiod, one was auto. I didnt notice much difference in what I needed to apply but I use box fans and 35rh.

So it probably would be drying out like hell right now like my drain to waste coco grow. Im at 12x a day feed right now. Just last few weeks flower and the rootball in this particular clone is thirsty unlike the others. Lots of dialing in to do.

Hope this helps, its fustrating I get it but everyone eventually finds what works. For me it was dtw coco not that Im perfect but I get to harvest. My issues are with mold right now.
 

medidedicated

Well-Known Member
It was with fox farm ocean forest so maybe its just not a good soil anymore idk. People do fine with it though so I really dont know. People can say lots of reasons it is but to this day idk what happened but I followed peoples advice, the half that wasnt killing my plant. Half said overwatering and overthinking it but I doubt that.
 

MtRainDog

Well-Known Member
Not sure if its an auto, but I will say it's going to be more difficult to water correctly when you have a small plant in a large container. I always go from solo cup > half gallon nursery pot > 1 gal pot > 3 gal pot > 5 gal pot... you get the idea, but yes always up-potting. Much easier to water by feel when the roots actually fill the container.

VPD doesn't mean much to me. There's only so much I can do for climate control, and I just have to live within those parameters, and they aren't ever ideal VPD numbers and I seem to do just fine.

Sometimes it's just a slow plant, sometimes it's new-grower syndrome that has you endlessly mess with things. Anyway, I think your plant looks fine. It's small and slow sure, but I think once those roots are happy, she'll take off.
 

GreenGenez421

Well-Known Member
Chasing VPD will drive you to the looney bin. Focus on ambient temp and RH. Once you get dialed in with everything else then start tweeking VPD. But honestly you really need to have complete control of managing your environment ( heating, air-conditioning, dehumidifier, C02 enrichment and ppfd monitoring) in order to get any true benefit out of chasing VPD.
 

MtRainDog

Well-Known Member
Going by weight of bag might work better for you......feel how heavy it is dry so you know when to water. Another option would be go to a wick watering system......takes all the guess work out of the equation. Bottom watering/feeding may work better for you......I just fill a tray under plant as long as it absorbs it within an hour. Anything left I pour off.
I never let my FF get as dry as yours....it will easily get hydrophobic.
I agree, bottom watering would benefit the OP. I always bottom watered SIP style when I ran autos. Took all the guess work out of watering little seedlings in large containers.
 
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