Over preasure during grow and early flower. Anybody?

[HushemFlupskluk]

Hi! Recently I joined this community to learn more about growing Marijuana. Mayor motivation to join was the vertical/colosseum community since I fell in love with these setup type grows.

This vertical setup alowed me to yield much more then I expected. It alowed me to cross the 1 GPW goal much sooner then expected. And besides I believe I can improve to over 2 GPW. Which is insane. Who ever expected that this is possible? Not me. 1 GPW seemed like one goal to one day achieve, somewhere in the future.

Perhaps the vertical setup is not my only yield-increasing technique. It could only be the positive pressure I used during 3/6 of my rounds (250W bulb).

How did I discover this? In a short overview I hope I can prove that this is one yield increasing technique which is for free! One would simply use the power input already consumed.

We switch the exhaust unit to the intake part of the growroom. The room will be pumped with air. The exhaust will be passive. This is what I tested during grow round 3.

That round I grew autoflowers of Royal Queen seeds the Royal automatics. In total that round lasted only 8 weeks from sprouting. Harvest dry was 100 gram.
The 1st 4 weeks of that round I used the positive pressure as explained above. The result was that some leafs looked awesome. Then I suspected that I had one yield increasing technique in use.
In comparison to round 4 in which I DID NOT USE this technique. Same seeds but lasting 10 weeks from sprouting. I only harvested that same 100 grams.
I decided to continue using the technique to grow extra good looking leafs which are much larger then the regular leafs grown in normal conditions.

My second round using this technique was round 5. 2 Royal queen seeds Northern Light feminised.
Here my dreams came true at first when my leafs started to become huge! In total 3 full weeks they had positive.

The plants were looking good back then.

I yielded 300 gram! Not even all areas were taken around the bulb. This was very exciting and motivated me to start a new round of Northern light seeds to improve my yielding skills.

Now round 6 is running. 1st July is harvest time. Same techniques were used but now from sprouting. In total 5 weeks of positive pressure.
And the result was there. One fan leaf finger reached ~11 inches long.

Now I am wondering who can confirm that this technique really is yield increasing. The percentage in improvement i.m.o. must be around 25%, maybe more.

Is this size leafs normal? Perhaps users here are not impressed at all!

Just let me know

 

[supermanlives]

i dont grow hemp. i want to get high not smoke rope

 

[HushemFlupskluk]

Aha so you don't smoke rope

Nice to meet you too

 

[tester]

Sounds interesting anyway.
Are there any other sources to back this up?

 

[HushemFlupskluk]

I'll have to wait. I know there must be a number of growers out there that use this technique. Some experts I communicated with told me there are some around.

Who knows if they are active on the forums.

 

[Scrogerman]

Hey man,
So, from what i understand, your creating vitually total positive pressure? pushing air into your room & allowing it to escape via the passive inlets which used to be your active outlet.

If thats right? thats all wrong & known to promote molds, How do you regulate everything, ever heard of VPD man? grow rooms need to have a balanced RH/Temp, i cant see how you could achieve optimum conditions using such a method, as far as i know your doing things completely oppisite of how you should be, but who am i to argue with results, thats what matters.
To me its got Budrot written all over it, but it doesnt seemed to have bothered you. or have i got it wrong?

please tell us more, how you manage environment/conditions etc? Cheers!

G'Luck!

 

[HushemFlupskluk]

Thanks Scrogerman,

Yes positive preasure. Yes I had mold, but I assume that came after 3 weeks of drying when I put it in jars in week 4. About 70% was lost.

My newb drying skills made mold manifest itself.

I did had higher air humidity values at night. Up to 55-60% in the final 2 weeks. And also in late drying I failed.

Round 6 (present) enabled me to improve those environmental conditions that should be maintained to prevent mold from manifesting during flower and drying. Now in mid flower I am abled to keep the humidity at 40-50%. I purchased special drying nets and also I will cut all buds b4 drying. I want all twiggs gone during drying. Because I believe it was the radiant humidity from those twiggs that supported the mold in manifesting.

During the period of positive preassure the values can be maintained optimal. Temperatures and RH (20c - 28 C. 65% max). After 1,5 weeks 12/12 I switched to active outlet with carbon filter. Normal conditions can be maintained also (50% max).

My room has active airflow fans mounted and also the whole airflow in/out now enables me to maintain the optimals. I am running maximal capacities a.t.m.

If needed I could cover my soil in an attempt to lower RH values a bit.

Thanks fro replying. It is helpfull!

And yes it is result that matters. Maybe I have to change my interpretations a bit to better understand what is going on with the plants.

Future will show me

 

[Scrogerman]

Ok i should of read your whole post lol, so you switched 1.5 wks 12/12 to active exhaust, i think that was a wise move. I dont buy positive pressure for dope, but whateva works for you man!

G'Luck

 

[HushemFlupskluk]

Active exhaust. I learn new words every day here man. Thanks again.

BTW I couldn't find any threads opened by this dude VPD man. Maybe I find more of it later.

Switching to active exhaust was nessecairy because of the odor. Otherwise I would have overdone it no doubt.

I noticed that this positive preasure enabled the plant to show some of its true potentions. But it only shows in a limited amount of nodes and only from node 4/5. Positive preasure during sprouting had no effect. Only after 2,5 weeks or so the plants started booming from node 4/5 and up.

I suspect overpreasure would have positive effects during an overpreasure period of about 3 weeks from node 4/5 and up until early flowering, say 1,5 week 12/12.

More would as said stimulate Mold manifestation.

Cheers!

 

[HushemFlupskluk]

Aha VPD is not a dude..

http://www.autogrow.com/vpd_calc.php

Here I found a calculator to practice on. I found that 24C/65% RH Makes ~1Kpa. This values I can reach easylly with my air intake unit supplied with a fogger humidifier. 1Kpa appearantly is the perfect value for the plants to be in

Using positive pressure and a fogger I can keep the temps low and the RH high.

This would IMO explain why on earth my leafs explode. Gaining productivity potention.

To be continued!!


PS Thanks for mentioning VPD

 

[daoboxer]

Crazy leaves Hushem...
Why no pictures of the flowers?
Interesting concept, what made you try this positive pressure technique?
Good luck in your quest....I'm watching along.
Peace.

 

[VerdantGreen]

i cant see how the 'positive' pressure is going to make such a difference... i cant even see how the pressure would be much higher anyway as air will escape from your passive exhaust...

what makes you think that this is the reason for your increased yields? it sounds like you changed quite a few variables like genetics, going vert etc.

VG

 

[HushemFlupskluk]

@ Doaboxer

This was my favorite.

What made me try positive preasure? I DIY an intake unit with which I have been experimenting with. It has watersupplie attached to it and functions as a humidifier also because a fogger is in it.

Testing this device I was confronted with this positive preasure. I suspected this to cause no harm to the seedling. Knowing that RH runs parallel to air preassure I thought it might be of good use in controlling my climate.
Also the growshop salesman first warned me that to much underpreasure would not support the seedling in their development. Thinking about this I basically visualised leafs expanding during positive preasure.

What else would a leaf do knowing underpreasure NOT support it; over preasure WOULD? It was just an imagination until I tried it in real life.

Appearantly considering my observations positive preasure must be the cause of those larger leafs.

I can't define it any better then what i have written down so far..

@ verdantgreen

Can't you read before posting? Answers are there.

 

[VerdantGreen]

@ verdantgreen

Can't you read before posting? Answers are there.

i did read before posting, you didnt mention all the other variables that could have influenced the grows. it could have been warmer temps or anything that speeded up the harvest, also different seeds of the same strain are not the same plant.

its a common fallacy to pin your 'success' on one factor when it could be lots of different things. did you even measure the pressure?

anyway never mind, i was just trying to be polite about my doubts in your methodology.

i wont trouble you again.... (although im interested in how 100g under a 250hps = 1gpw)

VG

 

[HushemFlupskluk]

''its a common fallacy to pin your 'success' on one factor when it could be lots of different things. did you even measure the pressure?
''

Positive preasure in my tent had more benefits. The climate was better under control. This must have enabled me to reach optimal VPD man values. The overpreasure MOST LIKELLY enabled the leafs to grow this large. You can assume that my climate was close to optimals otherwise those leafs wouldn't have overdone that.

It was confirmed to me that this size leafs is kinda out of the extra ordinairy.

Now. My observations tell me that it must have been this positive preassure. I didn't activelly mess around with C02 so that wasn't it.
High temperatures could not have been it because then my VPD values are not close to the optimals.

I did't measure the preasure. I used 2 tubevents 100mm diameter 105m3 capacity EACH. Tent was pumped visually.

''also different seeds of the same strain are not the same plant.''

I don't understand your point from here on dude. Make yourself more clear please.

 

[HushemFlupskluk]

.. However I think that c02 could have been the mayor factor.

because the number of c02 parts per cm3 is increased!! Using positive preasure...

 

[HushemFlupskluk]

Alrite then. I have some articles in Dutch that confirm a better climate can be maintained using positive preasure. One claims to get higher yields in his vegetable growrooms under preasure.

http://archief.degroentenenfruit.nl/groentenenfruit/2011/03/22/nummer-12/Egaal-klimaat-met-dichter-foliescherm-en-overdruk.htm
http://archief.degroentenenfruit.nl/groentenenfruit/2010/04/27/nummer-17/Kas-op-overdruk-gunstig-voor-teelt.htm

 

[Big Eggy]

I reckon you'v got really small hands :wink:

 

[HushemFlupskluk]

It is not the largest of hands no.

But you get the picture I think

 

[HushemFlupskluk]

Appearantly positive preasure only enables me to maintain an optimal climate for my plants. This is most likelly why the plants grew so well and big.

It was not the positive preasure alone as I first thought.

Also appearantly a little bit over positive preasure should be used in order to maintain your optimal climate. To much would eventually not support the plants in their development.

Note;

In my room the air was pumped in from below. The upper part had a passive exhaust slightly opened.