I have a couple questions regarding humidity. I know the humidity level should be around 50% all the time. During the day time (lights on) my temp is around 78 at the canopy ( I vegged way to long to close to the light) nothing i can do this time around. The humidity is really low anywhere from 16-20. It is winter and very dry ( going to get a humidifier tomorrow). During the night my temp is 60, with the humidity at around 50%, (which is perfect so i think). I guess my question is what does the humidity do for the plant? Why should it be at 50%? I Know that if the humidity is too low the plant gets dry and brittle ( my problem now). Any input would be appreciated, Thanks a Lot.
Temp and Humidity The Importance?
- Thread starter MM3
- Start date
giggles26
Well-Known Member
It really does not matter to be honest. Will 45-55% RH give you optimal growth? Yea sure. But so will lower RH. Some strains like higher RH and some don't. I've done many successful veg's at 25% RH.
Optimal conditions for MMJ is temp 65-75(can be higher) and RH of 45-55%. But you gotta remember nature isn't perfect and we try to replicate nature as best as we can so I wouldn't worry about it to much.
On the plus side you will be great for RH in flowering as you don't want high RH as you can run the risk of mold and other nasty shit you don't want.
Just watch and love your girls and they will love you back. Give them food,water,light, and air and they will reward you for your hard work.
Optimal conditions for MMJ is temp 65-75(can be higher) and RH of 45-55%. But you gotta remember nature isn't perfect and we try to replicate nature as best as we can so I wouldn't worry about it to much.
On the plus side you will be great for RH in flowering as you don't want high RH as you can run the risk of mold and other nasty shit you don't want.
Just watch and love your girls and they will love you back. Give them food,water,light, and air and they will reward you for your hard work.
420inmyapt
Well-Known Member
Don't quote me... quote CropHouse Ltd (found it online)
What does humidity have to do with water and transpiration? There are many linkages. Air humidity affects the plant process like transpiration, water uptake, nutrient transport, cell turgor and growth. Also plant transpiration increases the humidity of the greenhouse air. The linkages may be complex but they are very logical.
High humidity restricts the transpiration, because very humid air is almost saturated with water vapor and cannot absorb much more. If very humid condition and much sun shine were to occur at the same time, the plant would get very hot due to low transpiration and lack of leaf cooling
Also, at time of reduced transpiration, the water uptake is low, and therefore transport of nutrients from roots to shoots is restricted. If the high humidity condition last for a longer period of time (e.g. a week) then the plants may suffer deficiencies. Especially shortage of calcium is very common is those conditions.
It is obvious that low humidity stimulates the transpiration, which is good. But at very low humidity the leaves loose so much water that the xylem flow cannot completely replace the water losses, and thus plants can not maintain turgor in the plant cell. Then the cell walls are not pressed outwards, and the plant cell not stimulated to grow. Therefore a low humidity for a long period of time generally results in shorter plans and smaller leaf area.
http://www.crophouse.co.nz/files/CG_H06_-_Humidity_and_plants_-_view.pdf
What does humidity have to do with water and transpiration? There are many linkages. Air humidity affects the plant process like transpiration, water uptake, nutrient transport, cell turgor and growth. Also plant transpiration increases the humidity of the greenhouse air. The linkages may be complex but they are very logical.
High humidity restricts the transpiration, because very humid air is almost saturated with water vapor and cannot absorb much more. If very humid condition and much sun shine were to occur at the same time, the plant would get very hot due to low transpiration and lack of leaf cooling
Also, at time of reduced transpiration, the water uptake is low, and therefore transport of nutrients from roots to shoots is restricted. If the high humidity condition last for a longer period of time (e.g. a week) then the plants may suffer deficiencies. Especially shortage of calcium is very common is those conditions.
It is obvious that low humidity stimulates the transpiration, which is good. But at very low humidity the leaves loose so much water that the xylem flow cannot completely replace the water losses, and thus plants can not maintain turgor in the plant cell. Then the cell walls are not pressed outwards, and the plant cell not stimulated to grow. Therefore a low humidity for a long period of time generally results in shorter plans and smaller leaf area.
http://www.crophouse.co.nz/files/CG_H06_-_Humidity_and_plants_-_view.pdf
Cool, But if my level is at 16 % in the day is the causing my leaves to dry up and become brittle? They are starting to Cup
420inmyapt
Well-Known Member
Read my post man... it will make sense. 16% is too low
"But at very low humidity the leaves loose so much water that the xylem flow cannot completely replace the water losses, and thus plants can not maintain turgor in the plant cell. "
Tugor means:
The state of turgidity and resulting rigidity of cells (or tissues), typically due to the absorption of fluid.
giggles26
Well-Known Member
If your that worried about it grab a humidifier and raise it up. They are cheap and can be had for 15$ at a thrift shop or walmart. If they are pointing up and canoeing that can be caused by heat stress, deficiencies, ph problems.
Or throw a bowl of water in there to raise the RH. Honestly I'm gonna say if they are drying up and brittle they are thirsty or heat stressed.
Your post wasnt there when I just replied to the other post, just read it, Makes sense thanks alot
Blowin' Smoke
Active Member
High humidity can lead to mold and other problems. As for heat, I had plants that where growing in a shed that got into the 90 to 100 degree range. Plants survived but where low grade. No stickiness. Normally I bitch and moan about trimming and the stickiness of it, but that stuff was like hay.
I threw a bowl of water in there today and plan on buying a humidifier tomorrow. I was thinking heat stressed as well / but with a combination of the humidity was doing the cupping. The soil is still moist, so I know thats not the issue. It could be the PH, I look into it.
Thanks for the advice
giggles26
Well-Known Member
No problem here give this a read. Will help out by allowing you to read your leaves. Helped me out a lot in the beginning.
There are several different symptoms that involve leaf curl. The direction of the curl, and particular leaf area effected will point you in the right direction.
Leaf Margins (edges) canoeing upwards like the letter "V", is a typical symptom of Magnesium deficiency.
Leaf Margines canoeing downwards is a typical symptom of excess Nitrogen. The tips are usually involved, and the leaf resembles an Eagles Talon.
Tips only pointing downward, is commonly caused by low humidity.
Tips only pointed up can signal too much heat, or the start of a nute burn.
Whole leaves pointed up is commonly a symptom of too much heat from the lighting.
Under watering will make the leaf soft and completely limp.
Very helpful thanks. Here are a couple of pics of my leaves and setup. Intake is a 6" duct fan with an oscillating fan by it. Outake is the same 6" fan light is about 18"-24 away right
now. Its as high as I can go right now due to over vegging.
djstirling
Member
Nice one very helpfull
smellzlikeskunkyum
Well-Known Member
wow there is some bad info in this thread. all strains that express major signs of either indica or sativa are going to require more extreme humidity levels. wether low or high. real pre98 bubba hates moisture. u have to keep the soil dry as fucc too. my grape ape loves humidity and moisture.
temp is the same way... but you are more likely to see a "middle line" where its best for everything. kinda like ph...
temp is the same way... but you are more likely to see a "middle line" where its best for everything. kinda like ph...
smellzlikeskunkyum
Well-Known Member
cold air = dry air too. hot air doesnt always mean high humidity tho.
smellzlikeskunkyum
Well-Known Member
i personally dont feel u can assume high temps or too much light with leaves going upward. some strains just do that. some strains do it when they dont have enough light.
smellzlikeskunkyum
Well-Known Member
that curling downwards its usually a nute thing... high N makes the leaves real dark too tho. ive noticed alot of chemdawg strains have curling leaves, but they are healthy plants. its not always a bad sign. usually is tho...
DaBIGCAT707
Member
Try putting your water reservoir in the room.. This will keep your plants moist but when its cutting time, take it out... It'll get too moist if you dont..Same idea greater effects... Also dont brew your tea in the room(if you do brew), can lead to infestations..
Also, humidity can depend on type of pots and how many plants you have.. Basically the overall moisture content through the air.. Too much= MOLD Too lil=dried out buds
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