82 degrees in flower ?
- Thread starter Fatleg77
- Start date
Lordhooha
Well-Known Member
What’s the rest of your setup looking like. I’ve never had temps that high but if the plants look fine then 82 is just fine. If they show signs of stress then you may want to correct it.
6ixtynin9
Well-Known Member
82 during flower is quite high. Depending on genetics, you may experience fluffy bud, fox tailing, reduced yield, etc. I grew out a cookie clone in the past and my AC took a crap. Temps varied between 80 - 85 whether lights were on or off. The shit had unlimited foxtailing and the buds never matured so I tossed the bitch. If your strains are of any of the Afghan variety, you may be able to get away with higher than normal temps.
GBAUTO
Well-Known Member
Only times I had any negative effects on runs that ended in the mid 80's were sativa dominant strains-they would fox-tail but all of the Indica dominant strains didn't show any negative effects. If you have the ability to get temps down then do it but if you're like me then do the best you can.
Roger A. Shrubber
Well-Known Member
quite possibly. the temp that really matters is the temp of your canopy. get a laser thermometer. they can be had cheap from amazon or ebay.
this is the best explanation i can find without actually putting a lot of effort into it
https://californialightworks.com/tips-tricks-best-practices-for-growing-with-leds/
this is the gist of it
78 degrees Fahrenheit (78F) is the widely accepted optimum temperature for most plants at atmospheric CO2 levels (360PPM). This number is actually misleading, because this recommendation is based on tests done with Sunlight or HID lighting, both of which have very high levels of Infrared light (IR).
When a leaf absorbs IR, it heats the leaf creating actual leaf temperatures of 5-7 degrees higher than the 78F degree air temperature. Thus with light sources rich in IR, an air temp of 78F is functionally 83F-85F to the plants metabolism. LED’s emit no IR, so to achieve similar metabolic rates found in HID or greenhouse conditions at 78F air temp,LED growers need to run the room air temp at 83F-85F. Air temp can also be lowered by 3F-5F in the last 2 weeks of flower to enhance ripening, but remember as relative humidity goes up the air temps go down, so be prepared to make adjustments accordingly.
Air temps higher than 85F can be run successfully with CO2 supplementation of 1000 ppm or higher. As ambient temperatures increase so can the levels of CO2 supplementation. (NOTE: CO2 concentrations above 3000ppm are dangerous to humans & pets.)
Root zone temperature needs to also be monitored. Running the air temp higher than 85F generally REQUIRES proportionally cooler dark period air temps to maintain an average root zone temp below 75F. Oxygen saturation in water drops off rapidly above 75F. So allowing the average root zone temp to get much higher than 75F will starve the roots for oxygen no matter how much oxygenation you provide to your nutrient tanks. Also, root pathogens prefer high-temperatures and low-oxygen conditions. So running room air temps above 85F can be challenging for all but the most experienced growers. Cooler nutrient tank (60-75F) temps can also help maintain the root zone below 75F without having to change the dark period air temp. Nutrients should never be cooler than 60f at the time of watering.
Every grow environment is unique, and there is no substitute for personal experience. We recommend you start low, i.e. 83F-85F air temp, and gradually work your way up through successive grows. Taking copious notes will make the differences from grow to grow, you will have a definite answer to what and where your efforts are or aren’t
this is the best explanation i can find without actually putting a lot of effort into it
https://californialightworks.com/tips-tricks-best-practices-for-growing-with-leds/
this is the gist of it
78 degrees Fahrenheit (78F) is the widely accepted optimum temperature for most plants at atmospheric CO2 levels (360PPM). This number is actually misleading, because this recommendation is based on tests done with Sunlight or HID lighting, both of which have very high levels of Infrared light (IR).
When a leaf absorbs IR, it heats the leaf creating actual leaf temperatures of 5-7 degrees higher than the 78F degree air temperature. Thus with light sources rich in IR, an air temp of 78F is functionally 83F-85F to the plants metabolism. LED’s emit no IR, so to achieve similar metabolic rates found in HID or greenhouse conditions at 78F air temp,LED growers need to run the room air temp at 83F-85F. Air temp can also be lowered by 3F-5F in the last 2 weeks of flower to enhance ripening, but remember as relative humidity goes up the air temps go down, so be prepared to make adjustments accordingly.
Air temps higher than 85F can be run successfully with CO2 supplementation of 1000 ppm or higher. As ambient temperatures increase so can the levels of CO2 supplementation. (NOTE: CO2 concentrations above 3000ppm are dangerous to humans & pets.)
Root zone temperature needs to also be monitored. Running the air temp higher than 85F generally REQUIRES proportionally cooler dark period air temps to maintain an average root zone temp below 75F. Oxygen saturation in water drops off rapidly above 75F. So allowing the average root zone temp to get much higher than 75F will starve the roots for oxygen no matter how much oxygenation you provide to your nutrient tanks. Also, root pathogens prefer high-temperatures and low-oxygen conditions. So running room air temps above 85F can be challenging for all but the most experienced growers. Cooler nutrient tank (60-75F) temps can also help maintain the root zone below 75F without having to change the dark period air temp. Nutrients should never be cooler than 60f at the time of watering.
Every grow environment is unique, and there is no substitute for personal experience. We recommend you start low, i.e. 83F-85F air temp, and gradually work your way up through successive grows. Taking copious notes will make the differences from grow to grow, you will have a definite answer to what and where your efforts are or aren’t
Beachwalker
Well-Known Member
Same here, I grow in temps up to 84° summers, no problem, no need for CO2. I do have to run the 1000HPS at 600 all summer though :-/
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bezalom
Well-Known Member
can't figure out what this low temps stuff is all about..
many places on the planet from where we get our favorite strains have late afternoon temps well above 90 degrees
ever heard of transpiration...increased transpiration from lower humidity and higher temps (and fan) make for increase in uptake of water along with nutrients making for bigger buds
I like my temps around 90+
I grow with LED's and add CFL's and shop lights to bring temps up
many places on the planet from where we get our favorite strains have late afternoon temps well above 90 degrees
ever heard of transpiration...increased transpiration from lower humidity and higher temps (and fan) make for increase in uptake of water along with nutrients making for bigger buds
I like my temps around 90+
I grow with LED's and add CFL's and shop lights to bring temps up
PURPLEB3RRYKUSH
Well-Known Member
Those temps are fine, my plants see temps over 110 in summer and still get good yields
Med68w
Well-Known Member
This article I read actually stated that led lighting needs higher temperatures. Check it out. I keep my cob led temps at 80-85 and their doing great.
https://www.blackdogled.com/lst
https://www.blackdogled.com/lst
Good post! 83-85F is great under LED. I'm running 29C/85F and they love it.
http://www.just4growers.com/stream/temperature-humidity-and-c02/vapor-pressure-deficit-the-hidden-force-on-your-plants.aspx
https://www.rollitup.org/t/leaf-temps-under-led-lec-hps.965610/
Roger, can leaves sweat? My RH has been 70-80 the last few days and I've seen a wet spot on a leaf a few times.
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Roger A. Shrubber
Well-Known Member
yeah they sweat, all the time, it's called transpiration. if you have thick leaf mass, grab the stalk every day and give it a good shake, you'll see wet spots on your leaves where they were touching each other.
Yeah, I just didn't expect they would skip the evaporation part of transpiration.
I guess it's just hard to evaporate in 80% RH!
And yes, it is a very think leaf mass. The girl just exploded near the end of veg, I hope I can finish without bursting the seams of the tent!
BTW, you had previously given me some advice about soil and pots etc..... I went with a Hempy bucket this time and it's amazing!
No more dirt!
She's as healthy as can be. The only imperfections are little burns from pushing up against the vertical LED strips in the corners.
I guess it's just hard to evaporate in 80% RH!And yes, it is a very think leaf mass. The girl just exploded near the end of veg, I hope I can finish without bursting the seams of the tent!
BTW, you had previously given me some advice about soil and pots etc..... I went with a Hempy bucket this time and it's amazing!
No more dirt! She's as healthy as can be. The only imperfections are little burns from pushing up against the vertical LED strips in the corners.
JSB99
Well-Known Member
When growing outside, temps can be higher. This is because of the massive amount of circulation outside, compared to limited, fan-based circulation inside.
Fatleg77
Well-Known Member
coreywebster
Well-Known Member
A lot of LED growers aim for 82. Its nothing to worry about provided everything else is in good range and plants are healthy.
I know folks who grow dank in high 80s.
I know folks who grow dank in high 80s.
Fatleg77
Well-Known Member
You should take a look at Black dogs website...it's the best science in my opinion on the led scene...they make the best led grow lights on the planet in my opinion
Roger A. Shrubber
Well-Known Member
yeah, it's the difference in IR that makes it necessary, temps in the high 70s give you good leaf temps with the ir from hps, led has no IR, doesn't provide as much radiant heat, so requires higher temps to achieve optimal canopy temps
JSB99
Well-Known Member
I'll check them out, but I'm actually going to build my own 16 cob led array soon.