my rh is 45%, but my leafs have moisture on them is that ok in flower ????

Msmagicbeans

Msmagicbeans

Active Member
my rh is 45%, but my leafs have moisture on them is that ok in flower ???? when i lift up a leaf that has been resting on a other leaf there is water on it.. will that be a bad thing im in flower my room is for sure at 45% rh
 
heckler73

heckler73

Well-Known Member
That's normal. I'm not sure on the biology of why, but I presume it is an effect of capillary action.
That's one reason to have a fan keeping them moving every once in a while. I believe if it is too still, those pockets can be havens for moulds, fungus, etc.
However, I am sure someone will come along to offer more detail. ;)
 
Msmagicbeans

Msmagicbeans

Active Member
heckler73 said:
That's normal. I'm not sure on the biology of why, but I presume it is an effect of capillary action.
That's one reason to have a fan keeping them moving every once in a while. I believe if it is too still, those pockets can be havens for moulds, fungus, etc.
However, I am sure someone will come along to offer more detail. ;)
Click to expand...
sounds right to me
 
Msmagicbeans

Msmagicbeans

Active Member
i added a extra fan and also removed some of the branches when i did my lollipoping to thin it out a little.. i had to remove some branches even tho they was going to the top, when i did my lst i kinda got way to any tops and 1 week in to flower and every thing under the first set of leafs was getting no light and i need light at least 12 inches down well at least some light any way, i think the thickness of the plant was causing it some to....... we will see
 
K

KryptoBud

Well-Known Member
It's normal, it's called transpiration. Plants shed water from stomates on the undersides of their leaves which is why you see it when one leaf is on another. As water evaporates from the leaves the roots can absorb more nutrient rich water from the soil.
 
a senile fungus

a senile fungus

Well-Known Member
hondagrower420 said:
It's called vpd.

Vapor pressure deficit.

It is not normal.

Google is your friend.
Click to expand...

You are confused about what is going on here and maybe also what vpd is...

OP's plants are transpiring, and the water vapor they release doesn't have anywhere to go, so it collects on the surface of the adjacent leaf. If airflow is adequate, the leaves will have air flow at the surfaces, both top and bottom, and that water vapor will be able to evaporate freely.

VPD is referring to the relationship between air temp and RH, and how those two factors affect the stomatal openings.
 
hondagrower420

hondagrower420

Well-Known Member
a senile fungus said:
You are confused about what is going on here and maybe also what vpd is...

OP's plants are transpiring, and the water vapor they release doesn't have anywhere to go, so it collects on the surface of the adjacent leaf. If airflow is adequate, the leaves will have air flow at the surfaces, both top and bottom, and that water vapor will be able to evaporate freely.

VPD is referring to the relationship between air temp and RH, and how those two factors affect the stomatal openings.
Click to expand...
Yeah, but he never said temp or if he had a fan.
 
hondagrower420

hondagrower420

Well-Known Member
Deficit
Vapour Pressure Deficit, or VPD, is the difference (deficit) between the amount of moisture in the air and how much moisture the air can hold when it is saturated. Once air becomes saturated water will condense out to form clouds, dew or films of water over leaves. It is this last instance that makes VPD important for greenhouse regulation. If a film of water forms on a plant leaf it becomes far more susceptible to rot. On the other hand, as the VPD increases the plant needs to draw more water from its roots. In the case of cuttings, the plant may dry out and die. For this reason the ideal range for VPD in a greenhouse is from 0.45 kPa to 1.25 kPa, ideally sitting at around 0.85 kPa. As a general rule, most plants grow well at VPDs of between 0.8 to 0.95 kPa [1]

In ecology, it is the difference between the actual water vapour pressure and the saturation water vapour pressure at a particular temperature. Unlike relative humidity, vapour pressure deficit has a simple nearly straight-line relationship to the rate of evapotranspiration and other measures of evaporation.
 
a senile fungus

a senile fungus

Well-Known Member
The water vapor in the air wouldn't condense onto a leaf surface unless the temp of that leaf surface is below the dew point of that air. Dew point tells you more than RH.

The water buildup on the OPs leaf is due to transpiration, the plant is breathing and when it exhales there is water vapor on its "breath".

Increasing airflow will evaporate the water.

I still don't understand what you mean when you call this " VPD". Care to explain?
 
K

KryptoBud

Well-Known Member
hondagrower420 said:
Deficit
Vapour Pressure Deficit, or VPD, is the difference (deficit) between the amount of moisture in the air and how much moisture the air can hold when it is saturated. Once air becomes saturated water will condense out to form clouds, dew or films of water over leaves. It is this last instance that makes VPD important for greenhouse regulation. If a film of water forms on a plant leaf it becomes far more susceptible to rot. On the other hand, as the VPD increases the plant needs to draw more water from its roots. In the case of cuttings, the plant may dry out and die. For this reason the ideal range for VPD in a greenhouse is from 0.45 kPa to 1.25 kPa, ideally sitting at around 0.85 kPa. As a general rule, most plants grow well at VPDs of between 0.8 to 0.95 kPa [1]

In ecology, it is the difference between the actual water vapour pressure and the saturation water vapour pressure at a particular temperature. Unlike relative humidity, vapour pressure deficit has a simple nearly straight-line relationship to the rate of evapotranspiration and other measures of evaporation.
Click to expand...
45% rh is saturated?
 
hondagrower420

hondagrower420

Well-Known Member
a senile fungus said:
The water vapor in the air wouldn't condense onto a leaf surface unless the temp of that leaf surface is below the dew point of that air. Dew point tells you more than RH.

The water buildup on the OPs leaf is due to transpiration, the plant is breathing and when it exhales there is water vapor on its "breath".

Increasing airflow will evaporate the water.

I still don't understand what you mean when you call this " VPD". Care to explain?
Click to expand...
Op never said if he had a fan for circulation.

I am basing my opinion on the fact that there is dew on his leafs during lights on.

If the op has a fan circulating air then the leaf is pulling from the air.
 
hondagrower420

hondagrower420

Well-Known Member
hondagrower420 said:
Deficit
Vapour Pressure Deficit, or VPD, is the difference (deficit) between the amount of moisture in the air and how much moisture the air can hold when it is saturated. Once air becomes saturated water will condense out to form clouds, dew or films of water over leaves. It is this last instance that makes VPD important for greenhouse regulation. If a film of water forms on a plant leaf it becomes far more susceptible to rot. On the other hand, as the VPD increases the plant needs to draw more water from its roots. In the case of cuttings, the plant may dry out and die. For this reason the ideal range for VPD in a greenhouse is from 0.45 kPa to 1.25 kPa, ideally sitting at around 0.85 kPa. As a general rule, most plants grow well at VPDs of between 0.8 to 0.95 kPa [1]

In ecology, it is the difference between the actual water vapour pressure and the saturation water vapour pressure at a particular temperature. Unlike relative humidity, vapour pressure deficit has a simple nearly straight-line relationship to the rate of evapotranspiration and other measures of evaporation.
Click to expand...
 
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