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Led temperature
- Thread starter davidw44
- Start date
bimblebrains_1
Well-known member
They do say at least 28c i think but i really struggle to get the temps up that high for most of the year,i still get good results and i dont recall the summer runs yielding anything more notable..this time of year my room runs at 22/23c and i put a little fan heater in my tent to keep it 18 ish lights off...seems to work just fine so i cant justify the extra electric it would take to use the fan heater lights on as well to achieve the 28c...i wouldent worry too much about the temps within reason is what im trying to say..sorry for the rant lol
Douglas.Curtis
Autistic Diplomat in Training
What is your end goal? Do you want loads of resin or loads of plant material? Hot/Wet grows a lot of plant material. Cool/Dry grows a lot of resin made of terpenes and cannabinoids. Complex terpenes and cannabinoids are formed from monoterpenes which are sensitive to high temperatures. The most fragile monoterpenes begin vaporizing away at 70F, which is why warm/hot grow rooms often smell so nice. 
When monoterps are continuously vaping off, they are not around to polymerize to more complex terpenes and cannabinoids. So if you really want flavors and loads of resin, keep your canopy temps below 70F and your humidity low enough to keep transpiration rates very high. (low 20's)
Either way, LEDs require more calcium than HID/Floros and soil biology does best in the mid 70's?
When monoterps are continuously vaping off, they are not around to polymerize to more complex terpenes and cannabinoids.
So if you really want flavors and loads of resin, keep your canopy temps below 70F and your humidity low enough to keep transpiration rates very high. (low 20's)Either way, LEDs require more calcium than HID/Floros and soil biology does best in the mid 70's?
bimblebrains_1
Well-known member
indeed Douglas,i get amazing resin production with my room 22/23c and low 30's humdity under these leds,i like farming resin not biomass too ;-)What is your end goal? Do you want loads of resin or loads of plant material? Hot/Wet grows a lot of plant material. Cool/Dry grows a lot of resin made of terpenes and cannabinoids. Complex terpenes and cannabinoids are formed from monoterpenes which are sensitive to high temperatures. The most fragile monoterpenes begin vaporizing away at 70F, which is why warm/hot grow rooms often smell so nice.
When monoterps are continuously vaping off, they are not around to polymerize to more complex terpenes and cannabinoids.
Either way, LEDs require more calcium than HID/Floros and soil biology does best in the mid 70's?
Three Berries
Active member
My winter grows are high CO2 (2000-3000) and I cannot give them enough Ca without a daily foliar spray of CaCl at 1300 ppm at 30 +days. Sometimes two times a day. I add to the soil too but hesitate for fear of getting too much there.
Getting better but if I do not then the leaf turns brown. I have one plant where the back side didn't get hit and it's quite apparent.
Getting better but if I do not then the leaf turns brown. I have one plant where the back side didn't get hit and it's quite apparent.
Switcher56
Comfortably numb!
... as I. It is where I started, and outside of my soso 1st run. I never had any issues to speak of. Especially after I switch nute lines.
I think you ‘re using too much power for your plants to handle and /or have your light too close to your canopy. during winters i have to drop about 10-15% of power i use compared to summer with the same hanging height for my Cree cobs.
Here’s a cut-n-paste of what i just wrote to another thread ..i’m too lazy to type it again:
If you grow in soil you can’t keep your leds as close to your plants - and/or use as much watts -as you can when you grow in coco/hydro, because in soil the plant tissue will dehydrate more easily. In hydro plants there is more moisture in the tissue so they can handle leds much better.
One thing you can do is that you turn your circulating fan(s) away from your plants, cause direct air blowing on your plants will make the dehydration issue worse.
If you struggle to get your temps and humidity close to the right levels for led growing, you can use a timer on your exhaust. During winter up here in N Europe i have my exhaust ON for 10-12 minutes every 90 mins in my small tent– but i have a circulating fan ON all the time during lights on, and i have it blowing at my cobs not at my plants
Three Berries
Active member
I was running 100w veg and a 50w red. I cut out the red tonight. see what happens. This in a 3x3x5'
Three Berries
Active member
The tent is down to 71F now but the humidity is high at 63% VPD .97
I prefer 75-78F. The quality is always better when cooler. Too cold/hot will cause issues.
I gather you can’t raise your lights any higher..? First step would be raising them abit but if your lights are as high in your tent as they can be, then you have to dim your lights a bit.
For people growing in a smaller tent/cab or have height restrictions, i’d say a dimmer is a must.
Three Berries
Active member
I tuned off 50w of lights and they don't seem so stressed. I didn't spray them last night or today yet. I want to water them to run off and get a pH reading.
YellowCanaryConsulting
Active member
Whoever started the "led needs heat" mythos actually added photosynthetically-active IR to their grow, not higher frequency radiation. Leds need a real light spectrum, not heat. Adding heat is going to help things flow, regardless of light. Which is why day/night differential is important.. Falls colors for example. Slow phosphorus creates a different carb profile above ground, which lends itself to glucoside pigment synthesis. Photorespiration takes over at 78° so in theory 77° is perfect leaf temp for any higher C3 plant
I've about had it with you Coloradians and your "cold and dry" supremacy! You've forced me to build a refrigerated grow room just to prove you Coloradiots wrong!
But first I'll cite some irrelevant paper:
pubmed.ncbi.nlm.nih.gov
See. Cold causes the hay smell. Now I don't have to build that room afterall.
Polymerization theory doesn't pan out. You may end up with high glass transition compounds, but what will they smell like at room temp or? Anyone? If you mean methylates acetates, etc, where do those come from? A properly harvested bud will smell sweet, and it's acidity and sharpness will perceivably increase over time. It's aroma and effect will increase, as the plant becomes more acidic and alcoholic. How does this happen. Not through synthesizing liquid terpenes. But by focusing on the primary metabolism from which the interesting secondary metabolites, not Leaflynenes, derive.
The low volume of volatiles in today's cannabis can be boiled down to 2 factors: Breeding for growing metrics instead of smoking metrics, and metabolic waste in the plant not being broken down into volatile alcohols, acids, oils, and water.
You're in soil now Douglas. You need to update the bro science. Think about organic matter. To decompose organic material into volatiles, and water, knowledge on the formation of low molecular weight carboxylic acids is important. Low molecular weight carboxylic acids are usually the refractory materials in wet oxidation of organic waste.
The agnostic viewpoint is to create liquids and turn them solid. The alchemical approach is to create solids and break them down into gases. Show me the refrigerant in a skunks anal gland Douglas.
The world has been led to view the universe as having been built upon nothing, while it is obviously not an addition to nothing,but a subtraction from everything. Simple math tells us this. The terpene synthesis pathway in Cannabis is like a Satan, imitating the spirit of God, yet in compete reversal. It's ironic that you soulless Coloradians can't grasp the nature of reality, what the universe is; the rotting corpse of a dead god.
I've about had it with you Coloradians and your "cold and dry" supremacy! You've forced me to build a refrigerated grow room just to prove you Coloradiots wrong!
But first I'll cite some irrelevant paper:
Green leaf volatiles protect maize (Zea mays) seedlings against damage from cold stress - PubMed
Although considerable evidence has accumulated on the defensive activity of plant volatile organic compounds against pathogens and insect herbivores, less is known about the significance of volatile organic compounds emitted by plants under abiotic stress. Here, we report that green leaf...
pubmed.ncbi.nlm.nih.gov
See. Cold causes the hay smell. Now I don't have to build that room afterall.
Polymerization theory doesn't pan out. You may end up with high glass transition compounds, but what will they smell like at room temp or? Anyone? If you mean methylates acetates, etc, where do those come from? A properly harvested bud will smell sweet, and it's acidity and sharpness will perceivably increase over time. It's aroma and effect will increase, as the plant becomes more acidic and alcoholic. How does this happen. Not through synthesizing liquid terpenes. But by focusing on the primary metabolism from which the interesting secondary metabolites, not Leaflynenes, derive.
The low volume of volatiles in today's cannabis can be boiled down to 2 factors: Breeding for growing metrics instead of smoking metrics, and metabolic waste in the plant not being broken down into volatile alcohols, acids, oils, and water.
You're in soil now Douglas. You need to update the bro science. Think about organic matter. To decompose organic material into volatiles, and water, knowledge on the formation of low molecular weight carboxylic acids is important. Low molecular weight carboxylic acids are usually the refractory materials in wet oxidation of organic waste.
The agnostic viewpoint is to create liquids and turn them solid. The alchemical approach is to create solids and break them down into gases. Show me the refrigerant in a skunks anal gland Douglas.
The world has been led to view the universe as having been built upon nothing, while it is obviously not an addition to nothing,but a subtraction from everything. Simple math tells us this. The terpene synthesis pathway in Cannabis is like a Satan, imitating the spirit of God, yet in compete reversal. It's ironic that you soulless Coloradians can't grasp the nature of reality, what the universe is; the rotting corpse of a dead god.
Douglas.Curtis
Autistic Diplomat in Training
tl, almost did not read lol
Will reply after work tonight.
Will reply after work tonight.
Redrum92
Well-known member
Whoever started the "led needs heat" mythos actually added photosynthetically-active IR to their grow, not higher frequency radiation. Leds need a real light spectrum, not heat. Adding heat is going to help things flow, regardless of light. Which is why day/night differential is important.. Falls colors for example. Slow phosphorus creates a different carb profile above ground, which lends itself to glucoside pigment synthesis. Photorespiration takes over at 78° so in theory 77° is perfect leaf temp for any higher C3 plant
I've about had it with you Coloradians and your "cold and dry" supremacy! You've forced me to build a refrigerated grow room just to prove you Coloradiots wrong!
But first I'll cite some irrelevant paper:
Green leaf volatiles protect maize (Zea mays) seedlings against damage from cold stress - PubMed
Although considerable evidence has accumulated on the defensive activity of plant volatile organic compounds against pathogens and insect herbivores, less is known about the significance of volatile organic compounds emitted by plants under abiotic stress. Here, we report that green leaf...
See. Cold causes the hay smell. Now I don't have to build that room afterall.
Polymerization theory doesn't pan out. You may end up with high glass transition compounds, but what will they smell like at room temp or? Anyone? If you mean methylates acetates, etc, where do those come from? A properly harvested bud will smell sweet, and it's acidity and sharpness will perceivably increase over time. It's aroma and effect will increase, as the plant becomes more acidic and alcoholic. How does this happen. Not through synthesizing liquid terpenes. But by focusing on the primary metabolism from which the interesting secondary metabolites, not Leaflynenes, derive.
The low volume of volatiles in today's cannabis can be boiled down to 2 factors: Breeding for growing metrics instead of smoking metrics, and metabolic waste in the plant not being broken down into volatile alcohols, acids, oils, and water.
You're in soil now Douglas. You need to update the bro science. Think about organic matter. To decompose organic material into volatiles, and water, knowledge on the formation of low molecular weight carboxylic acids is important. Low molecular weight carboxylic acids are usually the refractory materials in wet oxidation of organic waste.
The agnostic viewpoint is to create liquids and turn them solid. The alchemical approach is to create solids and break them down into gases. Show me the refrigerant in a skunks anal gland Douglas.
The world has been led to view the universe as having been built upon nothing, while it is obviously not an addition to nothing,but a subtraction from everything. Simple math tells us this. The terpene synthesis pathway in Cannabis is like a Satan, imitating the spirit of God, yet in compete reversal. It's ironic that you soulless Coloradians can't grasp the nature of reality, what the universe is; the rotting corpse of a dead god.
FWIW plenty of people get decent smells and tastes in lower temps. Not saying it's ideal, but I also don't think it that binary. I also think humidity makes a huge difference.
Three Berries
Active member
I find the humidity much easier to control with temps in the upper 70Fs. Below that and it gets to humid or too cold with ambient in the mid 60Fs. A 100w led doesn't get warm enough in my tent.
Cannabis loves heat in its veg cycle. There's a huge difference between winter/Summer plant health in veg. I don't use LED in veg because they can't provide the heat needed. Im not adding heat lol. Ive tested LED enough in veg during winter to see they don't work well.. Cold roots will cause really bad stalling, PH issues, and the medium stays too wet for too long(root rot) and they don't get a proper wet/dry cycle. Only new growers tend to go with bro science lol. Do all your own testing regardless of what's posted on the net. Once you get that experience you will know whos full of shit and who isn't lol. Growing cannabis isn't rocket science lol. They love a much higher temp in veg. IMO 85-90f is my sweet spot for veg, they love it.... Occasional 100f is fine. They will start to suffer at 110f. As I always say test it and see what works best. Growing healthy cannabis plants isn't hard once you get the basics down. The real test will be fixing unhealthy plants.
