VPD vs. humidity?

[Delps8]

The prices are still that here where I live, and considerably more if you want top shelf.

Seriously! Where's that?

"considerably more" - I quoted prices from a delivery service here in SoCal. Their top

[time passes - checks prices again]

Their premium products are >=34% THC (how do they do that?). They have one at $650 per ounce, a couple at $600, and the other half dozen at $500. Wow.

 

[Keffka]

a new local has just spent $2600 cdn on a 2x2 and a 3x3 tent and gawd knows what and killed 3 grows straight. he keeps killing seedlings like it was a business. he's not set up quite right and we can't get him to listen.

myself and a friend have been trying to coach him, i want him to join here but he's paranoid, his wife is super sketching, and i think she managed to sink some good decisions.

And this person will likely blame everything but himself for his issues.. you just can’t help some people.. especially if they don’t want to be helped.

Understanding basic gardening concepts is far more important than spending gobs of money on things people don’t need.

 

[Keffka]

Hah, we don't need no stinkin' facts!

It's still "rubbish" and VPD charts are stupid So there!


And "not a well understood measurement to sell people more crap they don't need".
Yes!!! We are victims!!!

And those "capitalists" (evil, evil people doncha know!) are exploiting "measurements" - the bastads!

Think about how evil they are. Take Pulse as an example. They developed a product, made the information about it available to anyone who can access the internet, and then they send things to people when people send them money. Evil, evil, capitalist.

============

What wankery…this thread. Not 420's finest.



That poor OP who wasn't clear on low RH vs low VPD and we send the poor SOB this dreck. I'd have to laugh if the fellow never came back.

Let's talk about something less contentious — politics anyone?

Not sure what points you’re trying to make.. you’re all over the place. If you’d like to have an actual conversation I’d appreciate you turning down the smarmy attitude.

 

[Delps8]

Not sure what points you’re trying to make.. you’re all over the place. If you’d like to have an actual conversation I’d appreciate you turning down the smarmy attitude.

I'm addressing multiple issues.

Sorry it came across as "smarmy".

I'm trying to bring some levity into the issue.

One poster made a "statement of fact" that was completely twaddle and you had to apply reality. My comment to your posting was "tongue in cheek".

Your comment about "capitalists". I was surprised you would make that statement You have a military background and your MOS tells me something about you*. I wouldn't have expected to see you make that statement so I engaged in a little leg pulling/sarcasm/jesting. I'm sorry it didn't come across that way and I will take pains to be more direct in my communication. Please accept my apology.

*I'm a former paratrooper and field artillery officer which is the basis of my appraisal of you. Heck, I was even in an AVIM unit for a while, so tip o' the hat to you.

 

[Keffka]

I'm addressing multiple issues.

Sorry it came across as "smarmy".

I'm trying to bring some levity into the issue.

One poster made a "statement of fact" that was completely twaddle and you had to apply reality. My comment to your posting was "tongue in cheek".

Your comment about "capitalists". I was surprised you would make that statement You have a military background and your MOS tells me something about you*. I wouldn't have expected to see you make that statement so I engaged in a little leg pulling/sarcasm/jesting. I'm sorry it didn't come across that way and I will take pains to be more direct in my communication. Please accept my apology.

*I'm a former paratrooper and field artillery officer which is the basis of my appraisal of you. Heck, I was even in an AVIM unit for a while, so tip o' the hat to you.

well I feel like a bit of an ass and apologize myself.. I really wish tone was able to be inflected better through text because I easily would’ve caught that if I would’ve heard it as opposed to reading it.
Perhaps a color coding system or something to show tone lol.

I was a bit stunned because I really tried to be fact based while being appreciative of the more simple earthen styles. That’s likely what caused my knee jerk reaction of being pretty fragile in my response lol.

My relationship with capitalism is a complicated love/hate one. I think it is inherently exploitative and directly responsible for many of the problems facing our planet. However, I acknowledge that it is the lesser evil of the choices. Humans are the problem really. We ruin most systems of governance by being peopley. Communism and anarchism both in theory are great systems that would benefit humanity and the planet greatly. As long as no human is involved in any of the decision making or governance at all lol. So that leaves us with reality. Reality is, so far, capitalism is really the best choice. So until we figure out a way to govern without human error or fallibility, I’m stuck being upset that I prefer capitalism lol.

 

[Preston9mm]

Meh... fuck it. I'll add my 2 cents....

I've grown for around 8 years now. Never even owned a ph meter.... let alone a par meter or any of the fancy gear. I fucked up alot of plants, but learned even more.

I'm sure any part of growing cannabis can be organized into stats & graphs to make a slightly better plant (in a perfect grow facility). Most home growers are nowhere near maximizing the capability of their plant in the first place because we don't have perfectly built grow facilities.... it's a moot point for most.
This kind of shit gets new growers chasing their tails & making no progress.
Keep things simple & great results will become simple.

 

[Keffka]

Meh... fuck it. I'll add my 2 cents....

I've grown for around 8 years now. Never even owned a ph meter.... let alone a par meter or any of the fancy gear. I fucked up alot of plants, but learned even more.

I'm sure any part of growing cannabis can be organized into stats & graphs to make a slightly better plant (in a perfect grow facility). Most home growers are nowhere near maximizing the capability of their plant in the first place because we don't have perfectly built grow facilities.... it's a moot point for most.
This kind of shit gets new growers chasing their tails & making no progress.
Keep things simple & great results will become simple.

No one wants to hear “learn the basics”. Heck, I didn’t want to hear it (I distinctly remember being frustrated hearing it lol). However, learning the basics is absolutely a game changer. The basics will increase your results far more than any of these efficiency modifiers will. In my experience here, the majority of folks asking questions like OPs, could do with learning the basics a bit more before they venture into efficiencies and maximizing quality/production.

VPD is a great tool for an experienced grower (especially organic folks). However, if you’re still learning the basics of growing our plant, it’s an extra step that’s likely going to frustrate more than help.

 

[bluter]

Their premium products are >=34% THC (how do they do that?). They have one at $650 per ounce, a couple at $600, and the other half dozen at $500. Wow.

there's a glut here. dispensaries are dumping mids at $50 - $60 cdn an ounce. top shelf is closer to $80 - $100, but there is back door pricing equal to the mids if you ask.

one place here has a ' zip in for $50 ' sale every thursday on one or two strains.

 

[Mayne]

well, heres my 0.04 cents

At the end of the day, its really about,,,,,,,,,,,,,,,,,,,,,,,,,,,,DEW POINT!!

Not 1 time has this word printed in the thread unless i missed it.
THAT, is what is the primary point of VPD,
Sure, plants grow in anything, they grow outside, noooo problem. Guess what else alot of out side plants do?
ROT
And guess what else,,,,,,,,,
PM
Because of the dew point was triggered.
also, higher humidity, airier, lanky buds.

Id rather have a shit light, then shit temp/humidity/dewpoint factors and ways to adjust them.

I perrtelilticly have a rule of thumb.

10 degrees difference in veg ( 75F-65RH)
15 degree difference in flow (70F-55RH)
And stay at those figures night and day.
No, its not rocket science, but it is, Atmosphere science.




Cheers> Im ready for the tomatoes, fire away

 

[Phytoplankton]

Here's my thoughts, VPD is, at best, a guide. Many sites claim that the "perfect" VPD produces more yield, but I have yet to see any hard evidence, studies ,or anything else with cannabis to prove it (if anyone has a truly scientific study, I'd like to read it). My guess is it does probably help some, BUT, does it add enough yield to justify spending a buttload of money on timers, monitors, dehumidifiers, rehumidifiers, heaters, and chillers? Aside from that, how many threads do we have about how stressing a plant improves potency, so how does the perfect VDP figure into that? Inquiring minds want to know. (LOL) Playing devils advocate.

 

[Porky82]

Im gonna disagree with this kind of.. VPD has been known since at least 1936, here’s a link to the first study:



D. B. Anderson was the original proponent however it never caught on.

Probably could of just left it at this!

 

[LukeHighWalker]

As an indoor grower, I think it's about providing the best conditions to you plant to thrive as best as it can. I observed that more important than VPD is root temperature in order to get the ladies fit. I do calculate my VPD with help of an excel sheet, the very lean style. However, I turn my attention to VPD only throw veg time, as high RH is critical during flower because of bud rot. At least, when the budlets starts to show up, I change the way I handle RH to mitigate risk of bud rot.

 

[Delps8]

there's a glut here. dispensaries are dumping mids at $50 - $60 cdn an ounce. top shelf is closer to $80 - $100, but there is back door pricing equal to the mids if you ask.

one place here has a ' zip in for $50 ' sale every thursday on one or two strains.

Wow. That's great for the consumer but isn't that because of a lot of oversupply? I think I read something about the Ontario gov't losing money on cannabis sales, was it last year? Does that ring a bell?

 

[Delps8]

Here's my thoughts, VPD is, at best, a guide. Many sites claim that the "perfect" VPD produces more yield, but I have yet to see any hard evidence, studies ,or anything else with cannabis to prove it (if anyone has a truly scientific study, I'd like to read it). My guess is it does probably help some, BUT, does it add enough yield to justify spending a buttload of money on timers, monitors, dehumidifiers, rehumidifiers, heaters, and chillers? Aside from that, how many threads do we have about how stressing a plant improves potency, so how does the perfect VDP figure into that? Inquiring minds want to know. (LOL) Playing devils advocate.

$120± for the Controller 69 + the humidifier. It took me < 10 minutes to connect the three wires and then to set up the controller. And the C69 maintained VPD something like 98% of the time without me having to do anything but clean the humidifier tank and refill it.

Re. the delta in terms of the grow - up to/as high as/in the region of 20%.

Back of the envelope cost benefit - $200 (that was for the PulseOne 2 ½ years ago) and, worst case, 5% increase. My 2' x 4' tent yields at least a pound (anything less is a failed crop) which means that instead of 450 grams, I might get another ≈ ounce. With a better grow (800 gm) that's a few ounces. Weed here in SoCal is at least $250 ounce (top shelf is > $500) so my payback for the Pulse is one grow. QED

 

[bluter]

Wow. That's great for the consumer but isn't that because of a lot of oversupply? I think I read something about the Ontario gov't losing money on cannabis sales, was it last year? Does that ring a bell?

it's a mess here. there was a gold rush mentality when things were first legalized and most of the players over estimated demand, and under estimated how many would turn to legal home grow.

there also wasn't enough enforcement to end the black market. law enforcement simply stopped looking and started directing resources to other things. the non legal producers don't face the same administrative or production costs, and have reacted to legalization by drastically dropping the street price.

an ounce that used to carry a street price of $200 cdn or more has dropped to the $50 - $60 or less. legal dispensaries can't keep up with the pricing, and producers can't get costs to line up with that point while being profitable.

 

[Wastei]

Who pissed in your corn flakes? You can call me names all you want. I really don’t give a . I grow because I enjoy it and I don’t need some holier than thoe telling me that I’m not doing it to their standards. So you do what you want and I’ll do whatever I choose. My grow my choice. CL

I don't know if I came out the wrong way but I don't think I've ever called anyone any names? I'm not you and you're not me. I can't tell you what to do or how to grow your own herb and what you find important or not for your grow. It's your grow and your're free to do whatever you want with it, this is a hobby after all.

I'm just saying that if you follow VPD ranges your plant will be able to synthesize more light and uptake more nutrients and be healthier as a result. I was following these charts way before I even knew they existed and all of the ranges were already discussed on the early forums back in the day.

I'm sorry if you feel hurt by what I wrote but I'm only writing what I think, not what I want other people to do? I don't care about other peoples grows in that sense since they're not my business to be bothered with. I'm only here to help and more than happy to answer any questions but I'm a human being and must be able to speak freely without being judged along the way?

 

[Roy Growin]

I think the fact that there is so much debate on the subject demonstrates that is a measurement of questionable value at best. Some folk take a technical view of their grows and good for them

Personally, I've never measured anything except ml/L of feed - no ppfd, ec, vpd, par, lux nothing
I used to measure pH but quickly realized that about 3-5ml/L pH down will get me to somewhere around 5.5-6.5 and I'm not too bothered exactly where, and my plants don't give a shit either, as long as they are fed and look happy

Fan, light and stick 'em in a pot of something - I'm not trying to grow specimen spaceships, just a bit of weed for a stash
So call me an amateur - have been for the last 40 years or so

 

[Phytoplankton]

$120± for the Controller 69 + the humidifier. It took me < 10 minutes to connect the three wires and then to set up the controller. And the C69 maintained VPD something like 98% of the time without me having to do anything but clean the humidifier tank and refill it.

Re. the delta in terms of the grow - up to/as high as/in the region of 20%.

Back of the envelope cost benefit - $200 (that was for the PulseOne 2 ½ years ago) and, worst case, 5% increase. My 2' x 4' tent yields at least a pound (anything less is a failed crop) which means that instead of 450 grams, I might get another ≈ ounce. With a better grow (800 gm) that's a few ounces. Weed here in SoCal is at least $250 ounce (top shelf is > $500) so my payback for the Pulse is one grow. QED

Where does the 20% increase come from, your experience or from an actual side by side comparison, under controlled conditions?

 

[Keffka]

I think the fact that there is so much debate on the subject demonstrates that is a measurement of questionable value at best.

Personally, I've never measured anything except ml/L of feed - no ppfd, ec, vpd, par, lux nothing
I used to measure pH but quickly realized that about 3-5ml/L pH down will get me to somewhere around 5.5-6.5 and I'm not too bothered exactly where, and my plants don't give a shit either, as long as they are fed and look happy

I kind of agree but also kinda disagree lol.. There is very little debate about the merits of Ph, ec, par, etc. However as you state yourself, you don’t even bother with these measurements. I view VPD in the same light as well. You don’t need to know it to grow well, just like you don’t need to Ph, or measure Lux. Knowing it though can help you be in more control over every little aspect similar to the aforementioned measurements.

VPD itself isn’t up for debate, it’s a fact, like ph, ec, etc. Its efficacy and application for our uses though is definitely debatable, again, just like ph, ec, etc.

So call me an amateur - have been for the last 40 years or so

This here is why I respect and can appreciate anyone who doesn’t have an interest in it. People have been growing plants for far longer than this knowledge has been known; and despite what governments an abolitionists want us to think, cannabis isn’t some super secret black box plant that grows and has needs unlike any other plant. Basic good gardening practices are the single most important factor in any grow, more so than genetics, lights, measurements, etc.

 

[Delps8]

it's a mess here. there was a gold rush mentality when things were first legalized and most of the players over estimated demand, and under estimated how many would turn to legal home grow.

Yeh, first movers have the highest risk for failure.

"Pioneers take the arrows in the chest; settlers get the land."

there also wasn't enough enforcement to end the black market. law enforcement simply stopped looking and started directing resources to other things. the non legal producers don't face the same administrative or production costs, and have reacted to legalization by drastically dropping the street price.

Regulation is distorting the CA(lifornia) market, too. Staggering what you need to do just to get started in business…any business here in CA.

an ounce that used to carry a street price of $200 cdn or more has dropped to the $50 - $60 or less. legal dispensaries can't keep up with the pricing, and producers can't get costs to line up with that point while being profitable.

Got it. That's a death spiral.