Meeks' 2013 Dapper Grow Log

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nMEEKS

nMEEKS

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Im sorry if you've answered this before Im just prest for time at the moment but whats your ideal drying room temps and humidity? thanks again meeks
65 degrees 40 - 45 rh

Now to discuss some of the things I think about when I debate my drying temps and humidity. First things first, let me establish that it would be the most ideal to dry to buds at the lowest temperature possible, as close to 32 degrees or its chilling threshold, if it is sensitive, as possible. This is because by reducing the temperature of the room (and eventually the product) you will be drastically reducing the respiration rate of the buds. As I have talked about before, respiration without photosynthesis means you are depleting your sugar/carbohydrate reserves. Obviously now that you have cut the stems off of the root system, there will be no new sugar generated even though respiration continues. To maximize the amount of sugar in your final dried buds, you want to decrease the amount of sugar the buds burn through during the drying process by keeping temperature lower (lower temp = lower respiration rate by an average of 2-3x per 18 degree drop)

Now that I have established why you would ideally want to run close to freezing temperatures to maximize final sugar content of your dried buds, let me talk about why most people, including myself, run their temps as high as 65 degrees. Besides the obvious increase to cooling costs that would arise from maintain fridge-like temperatures, there is the issue of humidity control at lower temperatures to maintain a high enough VPD to dry out the product.

VPD, or vapor pressure deficit is something I have talked about once before, and is a very important concept to understand, especially for post harvest handling. It is a much better measure of the pulling force on the plant than humidity is. Relative Humidity is a measure of the amount of water in the air over the amount of water the air at that temp could hold. The water holding capacity of the air increases as temperature increases, so it takes more water in the air at a higher temperature to equal the same %RH. Here is a chart that displays calculated VPD values for different set temperatures and humidities (the green range is ideal for plant growth, and does not relate to my discussion of drying).
VPDchart

As you can see in the chart, the lower the temperature is, the lower to humidity must be to equal the same VPD. Without a high enough VPD, the plants will lose water too slowly and mold/mildew problems will arise in your drying room. As Big Cheese said, a common drying room setting is 65 degrees and 40-45% RH, which on the chart corresponds to a VPD of 1.15-1.30, and since we know this VPD works to dry buds fast enough to prevent disease problems, let's use it as a baseline. From the chart, it appears we could get the same VPD range if we set our drying room to 60-62 degrees and 35% RH, or at 70-72 degrees with 50% RH . . . but with temperatures lower than 60 degrees it is very difficult to get a high enough VPD to dry the product fast enough without achieving a 10-20% RH, which for most people is not possible.

If the concept of VPD being more important than humidity still isn't making sense, this is an analogy that made it easy to understand for me (numbers are for illustration purposes only, not actual VPDs):

Imagine two buckets. The first bucket is a 5 gallon home depot bucket and represents a room at 70 degrees. The second bucket is a 1 gallon painters bucket and represents a room at 40 degrees. The 'humidity' in both rooms is 50%RH and will be represented by filling both buckets to their half way marks. The VPD for each room is represented by the empty space left in the bucket.

At 50% RH, the half full 5 gallon bucket representing a 70 degree room still has 2.5 gallons of empty space (2.5gal representation of VPD). At the same 50% RH, the half full 1 gallon bucket representing a 40 degree room only has 0.5 gallons of empty space remaining (0.5gal representation of VPD). You can see that even with the same 50%RH, the VPD in the 70 degree room was 5x higher than at 40 degrees!




So to wrap up this answer, the best temps are the lower temps to reduce burning more sugar than you have to through respiration, but deciding what temp you want to dry at will depend on what VPD you are shooting for, and then how low you can maintain your humidity to equal your desired VPD at a set temperature.

I hope this helps you out, I like understanding the reasoning behind what I'm doing, but that doesn't make rule-of-thumb answers like the one BigC gave any less valuable!


-Meeks
 
nMEEKS

nMEEKS

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Good Afternoon Farmers! Today marks 6 weeks from when the White Skunks germinated, and it is also the last day of Week 1 Flowering! I am really glad I didn't wait any longer than I did to make the flip, these girls (especially White Skunk #1) are huge already and the stretch has barely begun! I am getting a solid inch of vertical growth every day right now, and multiple inches added to the width!

I took some photos yesterday on Day 6 of flowering:
Day 6 WS2
Day 6 WS5
Day 6 WS6
Day 6 WS1
Day 6 WS4
Day 6 WS3



Then I did some plant rotating and a light drench application of Azamax to avoid problems down the line.

Now here they are on Day 7 of Flowering / 6 Weeks from seed germination:
Day 7 WS1
Day 7 WS2
Day 7 WS3






These girls are out of control! :wideyed:



-Meeks
 
bigcheese510

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Sorry for clutering your thread with bs bro. Dude said he was pressed for time so i thought id help. I won't hijack your thread no mas.
 
jlr42024

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That's the reason to ask Meeks detailed answers based on scientific fact and then explained in a wary only Meeks can. A true gift you have thanks for your time and I apologize for letting someone elses hi jack suck me in I'm usually better then that I'm truly embarrassed.
 
nMEEKS

nMEEKS

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Sorry for clutering your thread with bs bro. Dude said he was pressed for time so i thought id help. I won't hijack your thread no mas.
Thanks Big C, you know your help and input are always welcome, I hope you continue to offer your experience here in the future!

Definitely would like to add a totally dialed in drying room. and trimming room. so important but you just don't think about it. Things are looking great nMeeks..
You and me both Dirk, plenty of things on the list for the next upgrade! I am pretty happy with how things look right now. . . still not a single foliar application of anything. . . all feeding has been done through drip irrigation with soluble salts, but I feel like they are a 9 out of 10 right now and I don't know exactly what they want. Time will tell I guess, my runoff is low right now, perhaps they are under fed or perhaps it is just a little stress from the Azamax as usual.

That's the reason to ask Meeks detailed answers based on scientific fact and then explained in a wary only Meeks can. A true gift you have thanks for your time and I apologize for letting someone elses hi jack suck me in I'm usually better then that I'm truly embarrassed.
Glad I could give you the answer you were looking for JLR.
 
bigcheese510

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Thanks Big C, you know your help and input are always welcome, I hope you continue to offer your experience here in the future!


You and me both Dirk, plenty of things on the list for the next upgrade! I am pretty happy with how things look right now. . . still not a single foliar application of anything. . . all feeding has been done through drip irrigation with soluble salts, but I feel like they are a 9 out of 10 right now and I don't know exactly what they want. Time will tell I guess, my runoff is low right now, perhaps they are under fed or perhaps it is just a little stress from the Azamax as usual.


Glad I could give you the answer you were looking for JLR.
youre the homie. a little banter aint gonna run me off.
 
nMEEKS

nMEEKS

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as always your shit is proper bro!

and i totally agree with you on the drying....cool is good!

peace
Cool is good, and air circulation is better! Good to hear from you Kush, I hope all is well with you and yours!

youre the homie. a little banter aint gonna run me off.
Glad to hear it!

Looking good bro defiantly widening out! Awesome structure and very healthily looking, what's your veg feeding consist of??
Thanks Pura, I put the first screen in place tonight on the larger plants and I think they should fill out the table really nicely! The structure on WS #1 in particular has me very excited, a great bushy plant in veg, the lower branches break out from the apical dominance without a problem.

In veg I feed:
1.33g MonoPotassiumPhosphate (MKP)
0.1g MOST (Micros from JRPeters)
0.1g Fe (13% Fe by volume)
1.6g Epsom Salts (MgSO4)
2.44g Calcium Nitrate
At these rates per gallon = 740 ppm
 
dirk d

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you know nMeeks, everytime i give my girls a shot of azamax or monterrey i notice my girls will be pissed. leaves end up all messed up and just crappy looking. really hate applying anything except for Teas.

That VPD chart you had was pretty nice. I was always told not to go above 50% RH. I'm in a very wet and Damp area. Was looking on that chart and it said i should be at 65% RH. seems so high. You never have problems with PM??
 
kushluvr

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im great bro, hope ur good as well?

air flow is key..........drying, flowering, vegging...doesnt matter......they all need it! with proper airflow....you can have any RH u want.....

even in damp areas like the PNW........i run in the 60's all the time........no pm ever!

peace
 
nMEEKS

nMEEKS

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you know nMeeks, everytime i give my girls a shot of azamax or monterrey i notice my girls will be pissed. leaves end up all messed up and just crappy looking. really hate applying anything except for Teas.

That VPD chart you had was pretty nice. I was always told not to go above 50% RH. I'm in a very wet and Damp area. Was looking on that chart and it said i should be at 65% RH. seems so high. You never have problems with PM??
You have seen the same thing with the azamax leaf funk huh? I do prefer biological control over chemical in theory, I'll give a tea or something similar a try next time. Thanks for the input!

The green range on the VPD chart is designed for greenhouse growth of tomatoes. . . although it should be very applicable to cannabis, I don't want you to think it is the end all best chart for our industry. As Kush said, PM will only be a problem with poor air circulation. The reason PM and humidity are often mentioned in the same sentence is because the PM spore, unlike other molds/mildews, can germinate in very high humidities without full on standing water. With proper air circulation there should never be a problem with PM, but when the air flow in the canopy is stagnant for too long, the humidity can easily go above 90% and that is when PM becomes a problem. I have run a range of humidities in this grow room, as low as 40% to as high as 80% for multiple weeks and have not had any PM issues so far.

im great bro, hope ur good as well?

air flow is key..........drying, flowering, vegging...doesnt matter......they all need it! with proper airflow....you can have any RH u want.....

even in damp areas like the PNW........i run in the 60's all the time........no pm ever!

peace
I am doing really well! I'm look forward to finding something special in this run of White Skunks and I am learning even more than I expected in my class on potted plant production!

what rh do you run on the pm cycles? same?

I leave my humidity set at 70% day and night right now, but my sensors throughout the room tell me that it has been around 60-62% this week. The humidity control at night would only be for disease prevention, since the plants stomates are closed they would hardly notice if it was dry or humid, which brings us back to air circulation being more important. The reality of the matter is that greenhouse growers would want the humidity at 70% both day and night, but don't usually spend the money on systems to control it that accurately. Our tomato greenhouse is usually between 65 and 80% RH during the day and I can only asume it is the same or higher at night when the fans are off with no outside air exchange, plus a lower night temp with the same water volume in the air = higher humidity, as I explained in my previous post about VPD.
 
nMEEKS

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Hey Farmers! I have a photo update for the White Skunk ladies on Day 9 of flowering! I put the screen in place on the larger plants yesterday and on the smaller plants just a couple hours ago, I think both tables should fill out very nicely and I am leaning towards a single screen per table at this point!

Day 9 WS Screening1






Day 9 WS Screening2






I hope everything is going well in your own gardens! Thanks for checking out my thread and have a great rest of your night!


-Meeks:snaphappy:
 
MendoCruz

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Good Afternoon Farmers! Today marks 6 weeks from when the White Skunks germinated, and it is also the last day of Week 1 Flowering! I am really glad I didn't wait any longer than I did to make the flip, these girls (especially White Skunk #1) are huge already and the stretch has barely begun! I am getting a solid inch of vertical growth every day right now, and multiple inches added to the width!

I took some photos yesterday on Day 6 of flowering:
View attachment 292531View attachment 292530View attachment 292528 View attachment 292533View attachment 292529View attachment 292532


Then I did some plant rotating and a light drench application of Azamax to avoid problems down the line.

Now here they are on Day 7 of Flowering / 6 Weeks from seed germination:
View attachment 292534View attachment 292535View attachment 292536





These girls are out of control! :wideyed:



-Meeks
How do you like the Atlas 1? I was thinking about getting one for my room.
 
nMEEKS

nMEEKS

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How do you like the Atlas 1? I was thinking about getting one for my room.
It works great for me and in combination with my propane burner. I want my CO2 augmented to between 800-1000ppm and by setting the Atlas at 850ppm it does a perfect job of maintaining that range. Thanks for checking things out MC!
 
delae632

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First things first, let me establish that it would be the most ideal to dry to buds at the lowest temperature possible, as close to 32 degrees or its chilling threshold, if it is sensitive, as possible.

Wait, what? $ound$ expen$ive...Do you do this? If so I would love to hear how and your thoughts on cost vs return.

I'll be sticking with the KISS method. IME 40-50% rh and 65-75 degrees is just fine for drying top shelf herb. I don't know how or why you would try to do this in 32 degrees...even after reading all that. Just seems like trying to re invent the wheel.

Everything loos killer as usual.

I hope all is well man.

D
 
nMEEKS

nMEEKS

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Your room is SUPER clean. I love your set-up! Prime work, buddy!!!
Thanks MendoC, I try hard to keep it looking that way!

Wait, what? $ound$ expen$ive...Do you do this? If so I would love to hear how and your thoughts on cost vs return.

I'll be sticking with the KISS method. IME 40-50% rh and 65-75 degrees is just fine for drying top shelf herb. I don't know how or why you would try to do this in 32 degrees...even after reading all that. Just seems like trying to re invent the wheel.

Everything loos killer as usual.

I hope all is well man.

D
Hey D, thanks for checking everything out, and obviously reading through the posts! I didn't do this, and I thought my whole explanation lead to the conclusion that it was not going to be easy/possible to do because you would need a close-to-zero %RH to get an equal VPD at 32F to what you have at 65F with 40-50% RH. I do exactly what you do and hope for the best, but more precise control of Temp and RH to equal a specific VPD will give you the most consistant drying times to make success/improvement/record keeping more easily accomplished.

To address the expense and possibility that the cost may be too great for the return. . . the return on post harvest pre-cooling and then cold storage of almost all our fruits and vegetables from the moment they leave the field to the moment they get set out on the grocery store shelf is enough to justify the cost, and that is a product that sells for at most a couple dollars a pound wholesale (refrigeration capacity requirement is based on weight of product to be cooled) versus our product that sells for a much much much much higher price per pound! With all that said, it is also important to note that drying is a preservation technique so it will limit decay after the moisture content is low enough and cold will not be of worth while benefit after that point. However, during the 4-8 days that your bud is still moist it is also still a great host for disease pathogens, which can be halted/slowed by lower temperatures and is reason enough in my mind to hope for a better drying room in future designs.

Everything is going, realizing I will need to be here in school next year still for just a single class in the Winter and Spring quarter because of scheduling. . . but life at the moment is very good! I hope everything with you is as good or better!

-Meeks
 
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