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Take The Vpd Poll. How Important Is It?

  • Thread starter Thread starter ShroomKing
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Take The Vpd Poll. How Important Is It?

ShroomKing 95 Replies 22,362 Views
Page 2 of 5 · Replies 21–40 of 96

How important is (VPD) Vapor Pressure Differential in your garden?

  • Total voters
    23
  • Poll closed .
#22
vdp is very important. once I added my ultrasonic fogger system to my veg room (9 disc with adjustable speed 80mm fan), I saw an immediate growth spurt with in the 1st week alone. I match it to my room temps, 82* and 75% rh. my rh before the fogger was 50% tops.

shroom king, your vdp chart is a bit different that my chart (below). orange being the target ratios. maybe the chart is stretched out for ease of viewing???

in flower I don't go over 55/60 tops no matter what the vdp chart says. but I have huge air movement in both rooms.
 

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#24
DemonTrich said:
vdp is very important. once I added my ultrasonic fogger system to my veg room (9 disc with adjustable speed 80mm fan), I saw an immediate growth spurt with in the 1st week alone. I match it to my room temps, 82* and 75% rh. my rh before the fogger was 50% tops.

shroom king, your vdp chart is a bit different that my chart (below). orange being the target ratios. maybe the chart is stretched out for ease of viewing???

in flower I don't go over 55/60 tops no matter what the vdp chart says. but I have huge air movement in both rooms.
Click to expand...
Do you have a link for that fogger?
 
#25
Mudskipper said:
The drier the air the better, as long as the temp is controlled. Higher humidity means the less the plant needs to search for moisture w/ its roots because it's absorbing what it needs(h2o wise) thru its leaves. End all means smaller flowers.
Click to expand...

there may be some truth to that. I know mj is different, but what about the tropical rain forests? rain forests have some of the greatest and most dense forests in the world. their running 90*+ and 100% rh day after day after day.
 
#26
Great replies everyone.

I personally have no control over VPD parameters in my grow room.
My flower tent holds steady at 82*f with 40-50% rh. I don't ever really have any issues. But I do get a few crispy leaves towards end of flower.
My vote. ...It means nothing....MuHaHaHa!
 
#28
YaBuddy321 said:
You mind taking a look at some pics?
Click to expand...
Not at all.point me to your thread so we dont clutter this one.

DemonTrich said:
vdp is very important. once I added my ultrasonic fogger system to my veg room (9 disc with adjustable speed 80mm fan), I saw an immediate growth spurt with in the 1st week alone. I match it to my room temps, 82* and 75% rh. my rh before the fogger was 50% tops.

shroom king, your vdp chart is a bit different that my chart (below). orange being the target ratios. maybe the chart is stretched out for ease of viewing???

in flower I don't go over 55/60 tops no matter what the vdp chart says. but I have huge air movement in both rooms.
Click to expand...
I always said there should be different charts for different plant species
.why would a vpd chart designed for lettuce be useful for pot?
So i would question where the charts came from and who made them. I have seen a few dif ones out there
 
#33
It definitely has merit, but I disagree with the ideal charts. As already pointed out in this thread there are at least 2 different charts. Each species is different and with cannabis varities and taxonomy all over the place, it would be very difficult to standardize at this point. Regional heritages of the variety may be able to be used, but I am not so sure the work has been done.
 
#35
DemonTrich said:
I know mj is different, but what about the tropical rain forests? rain forests have some of the greatest and most dense forests in the world. their running 90*+ and 100% rh day after day after day.
Click to expand...

There's so much foliage because of the humidity. Rainforests typically don't have deep massive root systems. The soil there is very alive, teeming w/ microbes and mycorrhiza. It's also why so many of the plants have evolved to have massive leaves etc.
 
#36
Mudskipper said:
There's so much foliage because of the humidity. Rainforests typically don't have deep massive root systems. The soil there is very alive, teeming w/ microbes and mycorrhiza. It's also why so many of the plants have evolved to have massive leaves etc.
Click to expand...


exactly why vdp is critical for a grower.

my sfv og x dmt has super huge fanleaves, 10" or greater fingers, in 4.7g pots currently in veg. most of us also inoculate our soil and add myco as well.
 
#38
There are many factors in determining "ideal plant growth" and in cannabis growing especially, this becomes extremely subjective.

There are odd relationships between photosynthetic rates and secondary plant metabolism. This important because that basically boils down to this:

Photosynthetic rates and resin production are not one in the same. Photosynthetic rates build plant material; including cell growth, multiplication, etc.

It is very possible increasing your rates and therefore yield, can take away from resin production.

But none of this has been studied in any detail with cannabis.....

@ShroomKing really nice looking!

I don't think you have to fix much
 
#40
mittenmedgrow said:
Vpd I would never spray that shit on my plants, sounds toxic.
Click to expand...


who is telling anyone to spray anything on their plants? you can raise your rh with a fogger system, which moistens the air, not foliar sprays the plants.

I don't worry about vdp in flower, veg only. I run max 60%, ideally 50%-60 any given time in flower.
 
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