Vpd Survey

[3 balls]

@1diesel1 Pacific Northwest huh? Let's hope we cant spot each other by the smell coming from our garages. ;) Ditto on the genetics factor! My Black Haze is like a canary in a coal mine!

 

[crimsonecho]

I’ve dealt with pm since the day I started growing, the Pacific Northwest breeds pm. No chart no graph no study is going to tell you how to deal with pm on an indoor grow. Once it bites you your bitten and have to deal with the consequences. I’ve found a lot has to do with genetics of a plant when it comes to pm. I’ve been infested at times in the past where I’ve had 4 strains flowering 2 had it real bad 1 mild and one couldn’t touch it. Once pm is introduced to your grow it breeds like wild fire. There’s no stopping it unless your proactive. I use dehumidifiers religiously. When I’m in flower I set it for constant dehumid. In veg recently I’ve kept it around 50%. And I do use the home depot units they’ve treated me rite for many years.

Yes no problem. I understand thats your angle. That doesn’t negate the fact that chart works however :) its just a trade off.
Thats all i’ve been trying to say. When we’re talking about these stuff we have to be multidimensional. Just saying it doesn’t work or its bullshit is not gonna cut it. It works, just a little risky in some aspects.
Thinking about it me and rootbound could be the only ones that actually used the given numbers. Me by pure coincidence and rootbound for experimenting. In both cases plants seem healthy :)
He got 5% increase and i’m doing very well :D

 

[rmoltis]

It is just a tool to determine how much water is coming out of the leaves.

Which is directly correlated to the amount of water & nutrients drawn up through the roots from the soil.

If you have a super low rh% the plant will release moisture and gases super fast leading to a faster water & nutrient uptake. I hear people saying the stomata close to prevent /slow down the process.
I personally believe if there is ample supply of water in the soil this doesn't happen. also when taking into account your low rh% environment causing a more rapid nutrient uptake. you must lighten your nutrient feed as not to burn the plant. coupled with more frequent waterings.

Vice versa if rh% is high the moisture release will be low causing slower water & nutrient uptake.
In this scenario you would water less frequently yet have heavier nutrient feedings.

It is only a tool to help dial in your environment. Remember it's all relative.

I personally used to have a rh% environment that so low it was unreadable showing 0%( probably below %10)

This caused more frequent waterings & lighter feedings.
All plants would yield between %25-%30 on extractions.

Just remember vpd as a concept is a tuning tool to help dial in your environment. throw out the chart & just understand the concept.

 

[1diesel1]

It is just a tool to determine how much water is coming out of the leaves.

Which is directly correlated to the amount of water & nutrients drawn up through the roots from the soil.

If you have a super low rh% the plant will release moisture and gases super fast leading to a faster water & nutrient uptake. I hear people saying the stomata close to prevent /slow down the process.
I personally believe if there is ample supply of water in the soil this doesn't happen. also when taking into account your low rh% environment causing a more rapid nutrient uptake. you must lighten your nutrient feed as not to burn the plant. coupled with more frequent waterings.

Vice versa if rh% is high the moisture release will be low causing slower water & nutrient uptake.
In this scenario you would water less frequently yet have heavier nutrient feedings.

It is only a tool to help dial in your environment. Remember it's all relative.

I personally used to have a rh% environment that so low it was unreadable showing 0%( probably below %10)

This caused more frequent waterings & lighter feedings.
All plants would yield between %25-%30 on extractions.

Just remember vpd as a concept is a tuning tool to help dial in your environment. throw out the chart & just understand the concept.

Thank you sir, you explained the concept so eloquently!

 

[thunderfudge]

In a sealed environment that vpd chart is life

 

[1diesel1]

In a sealed environment that vpd chart is life

Ditto, explain?

 

[Daikokuten]

In a sealed environment that vpd chart is life

For real? Do the leaves drastically react to humidity? This is gonna end in me building a Frankenstein tote to test, i can feel it.

 

[1diesel1]

In a sealed environment that vpd chart is life

Please explain the chart?

 

[3 balls]

GROWING WEED

Every time you think you know what you're doing, you realize...

 

[Daikokuten]

GROWING WEED

Every time you think you know what you're doing, you realize...

The trick is to never think you know what you're doing.

 

[thunderfudge]

This guy does a great job explaining it

 

[thunderfudge]

If you've ever experience your plants shutting down and almost cauterizinng themselves to stay alive....foliage "pinches" on the fan leaves and loses its sheen and eventually yellows and dies as the stems purple,then suddenly noticed you were at 80°+/40% rh,lol.youve had a vpd issue.lol

 

[thunderfudge]

I've had veg rooms at 80°/60% with beautiful plants go into a 80°/40% room and fall on their ass in 48 hours,same room sealed and unsealed.

Since I bloom/dry/cure in the same room,it dries out pretty well with a big dehu running for 2 weeks.the concrete floor is a sponge and the ac is a dehu as well.soni have to leave an open rez in the room,not run the dehu,and olug in a humidifier;wet the plant trays a fee times a day.At work I unplug the dehus and everything's in tables,they get a good daily feed,keep the temps under 78, and I usually dont have a prob

 

[PharmHand]

Tiny bits of pm..........



Mold spores become active at 60% relative humidity and above. Proper air flow is key and can stop it from taking hold but spores are everywhere. I take the safe route.

I run 2 70 pint dehumidifiers here to keep the house and grow under 60%.

And I run a humidifier too for keeping it above 40%.

What temps do you aim for in flowering? You’re probably closer to the ideals than you think.

 

[jumpincactus]

Dude we were agreeing with each other for sometime :)
Just we don’t seem to get our points across.
Just saying, lets not call vpd a bullshit cause its not. Lots of stupid practices to get healthier plants with more thc and stuff but keeping your plant happy and out of stress should logically get you the best results.
If you want to manipulate this process in order to get more resin. Thats a personal choice. Would it work? Possibly. Would it be a better plant overall? I don’t think so, you’re stressing it.

Well said homey, well said.:D VPD isn't BS but a lot of indoor growers find it next to impossible to achieve due to our air movement exhaust circulation systems. The guys running sealed rooms have a better time at maintaining vpd sweet spots. As you all have admitted fine cannabis can and is grown way out of the sweet spot.

But at the end of the day realizing a plants true genetic potential comes from providing a environment that causes the least amount of stress possible so the plants genetics can bring on all the attributes locked within the DNA of that particular pheno. VPD is a guide to perfection but how many home growers have the money space and equipment to reach that sweet spot. We all just do the best we can with what we have. For me and my setup the fabled vpd sweetspot is but a dream to chase, for now anyway. :speechless:

I want to give you all props for agreeing to disagree and keeping it civil and got it all turned around. Good job farmers!!!

 

[jumpincactus]

Yes no problem. I understand thats your angle. That doesn’t negate the fact that chart works however :) its just a trade off.
Thats all i’ve been trying to say. When we’re talking about these stuff we have to be multidimensional. Just saying it doesn’t work or its bullshit is not gonna cut it. It works, just a little risky in some aspects.
Thinking about it me and rootbound could be the only ones that actually used the given numbers. Me by pure coincidence and rootbound for experimenting. In both cases plants seem healthy :)
He got 5% increase and i’m doing very well :D

and you are correct vpd is "science" peer reviewed studied and published. It just sets the bar for perfect conditions many of us will never hit. :D

 

[MIMedGrower]

What temps do you aim for in flowering? You’re probably closer to the ideals than you think.

I have to compromise as I run different plants in all stages so I keep the flower room around 75-77 degrees.

Why so much reliance on a chart? It still is just another way to measure relative humidity?

I’m not arguing that the chart is correct. I am saying that it pushes the limits of safety in an indoor growroom. I can control temp and humidity. Temp is more important and I think new growers are using the chart to excuse high temps and high humidity.

 

[jumpincactus]

This guy does a great job explaining it

great video for peeps new to the term. Very understandable for the average laymen. :D

 

[MIMedGrower]

Here is a link from a company with an excellent explanation.

https://www.arguscontrols.com/resources/VPD_Application_Note.pdf

The only difference between the chart and using relative humidity is it shows the parameters for specific temps.

It is still just a way to measure and react to greenhouse conditions. There should be no big range of temps in an indoor room so keeping temp and humidity in proper range is fine.

It is not a chart of perfect parameters like said above. It doesn’t even tell the plants water use. It is just a way to estimate it.

 

[crimsonecho]

Well said homey, well said.:D VPD isn't BS but a lot of indoor growers find it next to impossible to achieve due to our air movement exhaust circulation systems. The guys running sealed rooms have a better time at maintaining vpd sweet spots. As you all have admitted fine cannabis can and is grown way out of the sweet spot.

But at the end of the day realizing a plants true genetic potential comes from providing a environment that causes the least amount of stress possible so the plants genetics can bring on all the attributes locked within the DNA of that particular pheno. VPD is a guide to perfection but how many home growers have the money space and equipment to reach that sweet spot. We all just do the best we can with what we have. For me and my setup the fabled vpd sweetspot is but a dream to chase, for now anyway. :speechless:

I want to give you all props for agreeing to disagree and keeping it civil and got it all turned around. Good job farmers!!!

Completely agreed man.
I’m just lucky that my environment is constantly at 0.7-0.8 kpa :)
I won’t make much effort to take it up for flowering tho haha. Again thats my trade off to conserve electricity, doesn’t negate the data and the science behind it.