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Old 12-03-2015, 03:44 AM #61
PrimalHaze
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Excellent posts growaway.

I like the concept of steering the plants Growing them definitely is a journey.

Thanks for the links heady!

-pH
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Old 12-04-2015, 01:03 AM #62
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"Balance is god, the growers mantra."

Well said.

Do you have a grow currently?
I have my usual outdoor grow well underway. I clone from over wintered mothers and plant out early which initiates harvestable flowering (bonus!) and then reveges hard becoming what i understand you youngsters call "monster clones". Stems thicker than my wrist when finished. I finally moved away from old landrace sativas to modern cultivars a few years ago. Yields and ease of trimming mostly motivated me. This season will see a mix of OG's, a GDP, and a real Durban Poison(still like this landrace too much to not grow it.) I live on the edge of the desert in the southern hemisphere. I do small indoor grows from time to time to produce new mothers and flower old ones. For work i look after up to 100,000 plants at any one time, a mix of tomatoes,cucumbers and peppers, all in hydro, but i still love my home grows, both for the end product and the process. Dont know how many grows i have left in me, so i thought it was time to share some of this info with others. I would love to photo and share but have lived with secrecy for too many years to feel comfortable with it. Hope i live long enough to see the stupid laws change. Anything that i can be of assistance with will be my pleasure to provide. Its just turned 420 at my place, BRB. Cheers.
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Old 12-04-2015, 04:48 AM #63
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great posts growaway! thank you for sharing your knowledge and experience!
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Old 12-04-2015, 11:11 PM #64
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great posts growaway! thank you for sharing your knowledge and experience!
You are welcome. The faster we help remove the growing mysticism and replace it with good horticultural science, the easier it will become for everyone to grow good quality meds at home. This seems like a really nice and well informed community, i look forward to picking others brains also. Thanks Mr. Blunts (or can i call you "Heady"?)
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Old 12-05-2015, 12:59 AM #65
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i prefer heady

not much of a mister...
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Old 12-08-2015, 07:26 AM #66
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Heady - Happy belated birthday bro! How I missed that the other night I do not know.

Growaway - I second heady's statement...awesome post, super informative. I've got a few little ones growing now and I've been applying the knowledge I've gained regarding VPD to how I manipulate the environment with satisfyingly effective results. They're currently residing in a 4x7 grow tent while construction of their new and bigger home is under...of which I am super excited about (shout out to Heady Blunts for helping me to finalize the design) I will post pics for all who are interested soon. There are a couple of terms that you've used in your posts that I am not as familiar with as I'd like to be and was hoping you wouldn't mind elaborating...temperature differential and mean temp. As simple a term they may be if you wouldn't mind breaking them down to me (and the rest of us) as though I (and not the rest of us) were an idiot it would be much appreciated.

Waxy - what up man...how's the room going? Figure out that whole furnace fucking shit up ordeal? The hours I spent reading/posting in your lung room thread were very informative times in the life of kowhite...

Peace and CBD grease.....
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Old 12-08-2015, 09:18 AM #67
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Originally Posted by kowhite View Post
Heady - Happy belated birthday bro! How I missed that the other night I do not know.

Growaway - I second heady's statement...awesome post, super informative. I've got a few little ones growing now and I've been applying the knowledge I've gained regarding VPD to how I manipulate the environment with satisfyingly effective results. They're currently residing in a 4x7 grow tent while construction of their new and bigger home is under...of which I am super excited about (shout out to Heady Blunts for helping me to finalize the design) I will post pics for all who are interested soon. There are a couple of terms that you've used in your posts that I am not as familiar with as I'd like to be and was hoping you wouldn't mind elaborating...temperature differential and mean temp. As simple a term they may be if you wouldn't mind breaking them down to me (and the rest of us) as though I (and not the rest of us) were an idiot it would be much appreciated.

Waxy - what up man...how's the room going? Figure out that whole furnace fucking shit up ordeal? The hours I spent reading/posting in your lung room thread were very informative times in the life of kowhite...

Peace and CBD grease.....
Cheers Kowhitee, thanks for the shoutout. Mean Temp. is the just average temp of the grow space across the course of 24hrs. If you were to sample temp each hour and add these values together, then divide by 24, you would get your mean temp. Temp differential is the difference between maximum temp and minimum temp. in a 24hr period. For example, if max 85F during the day and min 55F at night = Tdiff of 30F. Wider temp diffs and overall higher means temps are generally considered a generative measure in the grow space once flowering/fruiting is underway. These measures encourage assimilates towards flowering and fruiting plant parts in preference to the foliage provided the flower/fruit load dominates plant balance. Used appropriately, a very vegetative, slow n short, lower yielding variety can be encouraged to improve flower development and plant structure. Used poorly, or with the wrong variety, and you will get stretch like a bitch and/or "exhausted" plants that don't reach their genetic flowering potential.
Creating greater temp diffs that increase the overall mean temp tends to accelerate assimilate production and stretch and potentially improve yield(think warmer day temps with nights staying same). Greater temp diffs that lower the mean temp can reduce assimilate production and slow development and reduce stretch(think colder night temps with days staying the same).
These changes are relative to the 'normal' temps that you would use for a particularly strain for example with light intensity, CO2, and feed manipulation used to assist the process.
All this is great provided you have the ability to change and completely control day and night time temps (active heating and cooling systems). For most of us at home, we see the effects of on our plants of our inabilty to control changing mean temp and Tdiff. In our effort to correct it, we may smash our VPD to shit. Commercially, hydronic heating and evaporative fogging and/or A/C cooling systems are the growers friend but are not cost viable for most us at home. One day...
Still, knowing about it and doing what we can do to control or manipulate it can be the difference between an average result or a great one particularly under difficult climate conditions.
Once again, i have been asked a simple question and turned it into a wall of text. This new OG pheno i have just sampled could possibly be to blame...makes me rave on just a tad.
Cheers and thanks.
PS. 102F max temp in my part of the world today! Misting, irrigating, shading and venting time! Yehaaa!
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Old 01-19-2016, 08:03 PM #68
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Question: Right now my VPD # is way too high, and my plants have to use too much water from the soil, yaddy yadda. I cannot get my tent temps below 80F when lights are on no matter what I do. I have to hide smell, so no option for an AC (besides the very complicated process of a mini split or whatever, but that's not an option right now).

So since the temps are 80F - 90F, I need to increase the RH%. Right now it's at 45-55% when lights are on, not sure what when lights are off. It seems I need my RH to be at LEAST 70%, ideally 75-80%. That high of RH scares me obviously. However, something I hadn't seen addressed is using a carbon filter with the increased RH. If I do raise my RH to 70% with a humidifier inside the tent, won't that affect the carbon filter and make it fail? I heard high RH is the enemy for them. I have plenty of airflow, so I think going to 70% RH would be ok. Also not sure how the carbon filter / exhaust would affect the RH actually rising, since it would be exhausting the whole time, would the RH actually rise?
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Old 12-05-2017, 10:34 PM #69
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Great modern read & study on VPD

Anyone inside, in a tunnel, a GH etc, very relevant...


https://www.nature.com/articles/srep43461


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Old 12-06-2017, 06:48 PM #70
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thats a great article led

"Although the suppression of the driving force by reducing VPD resulted in a substantial reduction in irrigation, the fogging application also accounted for the water consumption to some extent. The trade-off between reduction in irrigation and the input of fogging water can be optimized by increasing the planting density and improving the fogging evaporative efficiency."

makes loads of sense
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