Growing Under LEDs at Temps Above 80F

Dion · Dec 1, 2020

SuperBadGrower said:
Yep 29°C... my shit reaches 35°C/95°F every summer and the plants are OK. if you think such temperatures causes problems with LEDs, it's probably a misdiagnosis, something else went wrong or its genetics

below 24 or 25 C (in my estimation) is where you get "plants dont transpire well under leds!!"
And below 22 C you get "led causes deficiencies!!"
the 2 most common 'led problems' ...

I've flowered in 40c with led
Not my best run but the attic is hot

Koondense · Dec 1, 2020

Damn that's hot!
My max temps ever in flower were "just" 38°C, for a whole week

Cheers

Dr.King · Dec 3, 2020

Hello all, hope all is going well. Currently using the spider farmer 2000 in a 3 x 3 x 7 tent at full power only 2 weeks in flowering. Years back when I was using cheaper leds I had leaf burning as some stated because of light intensity/them being to close. I noticed the same thing with the spider farmer 2000 this grow. My current sativa is only 10 inches away from the light and doing great now after double or even tripling my calmag. What most people don't understand about plants is light intensity, leds in general sap the calmag out of plants faster then being outside because they are so close to the plant. I had to do the same thing or give my OTH and Green Haze even more calmag in late flowering because they require so much light intensity to correctly flower/finish. Hope this helps and happy growing.

Creeperpark · Dec 3, 2020

You can bump it up in Veg stage, then reduce in flowering. When running higher temps the plant will transpire more water.

Dion · Dec 4, 2020

Dion said:
No 29c is the correct ambient temperature for growing under led.

You have obviously never grown under led, if U had U would know that at those temps photosynthesis slows to almost nothing

Keep in mind we need to compare apples to apples

So we are talking about environmental temperature under led

Leaf surface temperature is about the same as ambient under led

Under traditional lights leaf surface temp can be anything up to 7c higher than ambient.

IR has already been mentioned many times

I'm such a rude **** calling ppl out for bullshit misinformation

It's been fun icmag

Thanks to all the supporters and haters alike

New season, new chapter

Dion out

:thank you:

Koondense · Dec 4, 2020

What, again?

You should care less about other opinions, especially if not informed. Most are.

Waiting for your comeback dion

Fixer · Dec 7, 2020

The Master Kush is down. Everything reveged eventually. It's strange because there were two Mother's Milk right next to the MK that didn't react at all to the change of fixtures. Live and learn!

planttechniques · Mar 30, 2021

Prove me wrong on my theory.

1. LED's don't provide enough IR to heat the leaf surface to an appropriate VPD

2. Therefore, we need to add IR to our existing LED's

3. What's the most efficient way to do this, with an heat (IR) lamp of course. The bulb produces more IR than any other bulb.

https://en.wikipedia.org/wiki/Infrared_lamp

planttechniques · Mar 30, 2021

The Honorable Dr. Bruce Bugbee

https://www.youtube.com/watch?v=CJkW3SULYkM

https://www.youtube.com/watch?v=ncGOymKsQo4

Koondense · Mar 30, 2021

This has been speculated since the first leds came out, nothing new. Otoh, why use electricity for ir only when you can have ambient temps up for better vpd. It's about room management mostly...
My observation is some plants which were bred exclusively under hps show most deficencies under leds. Sometimes they also have issues under the sunlight...

Cheers

Legalcdn · Mar 30, 2021

If you want to heat a space when lights are off, infrared will give off light and mess with flower cycle. During lights on, infrared might work.

could add small uncovered CMH/HPS security light.

Legalcdn · Mar 30, 2021

Koondense said:
This has been speculated since the first leds came out, nothing new. Otoh, why use electricity for ir only when you can have ambient temps up for better vpd. It's about room management mostly...
My observation is some plants which were bred exclusively under hps show most deficencies under leds. Sometimes they also have issues under the sunlight...

Cheers

I find i get some deficiencies with african strains. I still grow the ACE gear.

Good point Koondense.

planttechniques · Mar 30, 2021

Koondense said:
This has been speculated since the first leds came out, nothing new. Otoh, why use electricity for ir only when you can have ambient temps up for better vpd. It's about room management mostly...

IMO, the issue with leds is that they do not warm the surface temp of the leaf enough. The issue isn't about whether the ambient temp is warm enough because ambient temp doesn't warm a leaf surface the same way that ir radiated heat does. IOW, why pay to heat the whole room when all that needs to be done is heat the leaf surface.

IMO VPD has more to do with the evaporation physics behind the temp:humdity ratio than the leaf surface temp.

Koondense · Mar 31, 2021

You don't pay extra for heating, you can just extract less heat. If the surrounding environment is in favor, of course.
During winters it's way harder to get great buds under leds if your temps are too low, maybe just add a hps in the tent, produces ir and par, probably the better choice over an ir lamp.

Cheers

planttechniques · Apr 1, 2021

Koondense said:
if your temps are too low, maybe just add a hps in the tent, produces ir and par, probably the better choice over an ir lamp.

The minimum HPS I could buy is a 250 watt.

I see these ceramic heat lamps on amazon and they run 50 watts an produce zero near red ir (visable light) so could be used at night.

If the ir heat lamp could produce the same effect at using 200 watts less than the hps wouldn't that be a better option because the LEDS I have already produce enough PAR, so much that I have to dim them down which actually reduces heat from the heat sinks.

chiesesganja · Jul 14, 2021

Koondense said:
Your friend is right, higher temps for led growing are ok. 28-30°C is a good environment for plants under leds, keep an eye on the humidity.

Cheers

yes it is

f-e · Jul 14, 2021

I got one of them ceramic lamp heaters. Like in many review, It got a good glow on, then popped.

CrustyCruz · Jul 29, 2021

You don't have to increase transpiration. Just increase strength of nutrients that are dependent on transpiration.

Pot growers are the most wasteful people on earth. Time to change. Wasting electricity to waste heat to waste water..

Growing Under LEDs at Temps Above 80F

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