LED's make Less Heat. Do plants Yield more in Higher Heat?

[Zealious]

?

I know adding like 2 cfl bulbs will add about 10 degress to my cab... Always could throw another LED unit in there as well. the 126w Penetrator adds about 10 degreees.

I love cfls.. I think you should most def add some cfls... esp a couple of 6500k ones.. this will help keep ur plants more compact in flowering and from my experience plants just perk up instantly to that light. there is simply more usable light.

as far as temps. personaly i think the plants enviroment requirements depend on the genetics.. I grow a lot of sativa/indica mixes and they do great at 80-85 veg and low 80 flowering.. however i have grown out a couple of heavy indicas that do terrible in those veg temps..

you have to think about the plants natural enviroment.. as well as evolution... alot of breeders grow indors so plants are becoming used to the comfy temps of 75 to 78

 

[Zealious]

i think temps are more important in hydro.. the temps can effect the uptake of nutrients.

 

[secondtry]

Like I said... the side be side will tell the story... Only difference in two identical rooms will be the lights.
photosynthesis = biomass, on any relevant level
It will be easy to tell.

until then unless someone bothers to show me calculations weighted for PAR efficiency and energy usage which show more usable photons per leaf with HIDs, I'm all set with believing you don't get the whole picture.

Irradiance is irrelevant if the radiation is 60% useless.

The bestest horti bulbs are 30% PAR

If the best "horti bulbs" are 30% PAR (which says nothing about irridiance) then the "irrelevant" radiation from the lamp would be 70%, that is 10% higher than the figure you wrote just above were you complain HID emit too much non-PAR photons. I assume that was just an error in math? Or a typo?...

 

[Zealious]

you guys are cracking me up.

THe only way to prove a theory is to perform a controlled scientific experiment.


And I volunteer to use cfls... I love the buggars.. I think I will make a air cooled 400w cfl light

If a 126w led can out perform a 250w hps and grow 2-4 pefect plants.. I think i would be sold..

 

[secondtry]

2) You can absolutely construct an LED array which has superior SPD output when compared to PAR. One array of LEDs can have many wavelengths if one so chooses. But there are points on the SPD where photosynthesis efficiency drops off rapidly so an LED array has the advantage of potential to taylor a more efficient spectrum.

3 )yes they do. I can find 275nm(uvb) 351nm 420nm 440nm 450nm 470nm 505nm 525nm 610nm 630nm 660nm and 940nm wavelength LEDs just on one led site...

Don't use see the what you claim in 2) and 3) is that you want to make a LED array that mimics HID's! Why not just use an HID which offers more PPFD? (esp. if considering "photoadaptation" which I wrote about earlier)

My statement which caused you to make those two claims was that LEDs are only a few nm in blue and red, and that is true. Show me one LED setup that offers all PAR wavelengths in blue and red?

RE: Green PAR:
I have already shown you the strong evidence that green is very important to consider under bright white light.

 

[Grat3fulh3ad]

Don't use see the what you claim in 2) and 3) is that you want to make a LED array that mimics HID's! Why not just use an HID which offers more PPFD? (esp. if considering "photoadaptation" which I wrote about earlier)

My statement which caused you to make those two claims was that LEDs are only a few nm in blue and red, and that is true. Show me one LED setup that offers all PAR wavelengths in blue and red?

RE: Green PAR:
I have already shown you the strong evidence that green is very important to consider under bright white light.

Not mimics... improves.

there are green LEDs.

Do custom setups count?

I'll just wait and see the proof of the grow, since you can provide none.

 

[secondtry]

you guys are cracking me up.

THe only way to prove a theory is to perform a controlled scientific experiment.


And I volunteer to use cfls... I love the buggars.. I think I will make a air cooled 400w cfl light

If a 126w led can out perform a 250w hps and grow 2-4 pefect plants.. I think i would be sold..

Hey there,

I don't see it as an unproven theory, what I have been writing is proven theory.

I agree real-world testing is best, but how do you measure the results? By what matrix? Not weight thats for sure. What needs to be used is what I wrote about, Pn, Pnnet and 3-day LI, along with ideally a probable spectroradiometer from OceanOptics or at least a quantum sensor from Li-cor for QY (from PPFD). These are the hurdles we have make to insure we end up with findings that are worth a damn (scientifically). If you guys want to donate to my efforts I will do all the testing, I live in a friendly state. I have many analytical tools/equipment I need buy and the sooner I get them the sooner we can have real-world answers to these questions...PM me if your interested.

You seem like a scenicy fellow, you may enjoy these pages, I find them good to read every so often they are in my top bookmarks

"How Not to do science"
Experiential Biosciences
http://www.ruf.rice.edu/~bioslabs/studies/concepts/concepts.html#not


"Fact, Hypothesis, and Theory"
Experiential Biosciences
http://www.ruf.rice.edu/~bioslabs/studies/concepts/objectivity.html

 

[Grat3fulh3ad]

I have told you over and over and over...
Measuring results is easy... photosynthesis = biomass.

 

[secondtry]

Not mimics... improves.

there are green LEDs.

Do custom setups count?

I'll just wait and see the proof of the grow, since you can provide none.

hey thanks for letting us chill out and converse like adults, I was getting a little heated too.

AFAIU the green PAR issue with increased Pn is under birght white light; and HID for example. I assume for two reasons: 1) as shown in the second paper I referenced above there is a synergist relationship between PAR ranges in photobiochemcial responses, so I assume the larger PAR wavelengths offered by HID allow the green PAR range to offer peak Pn; and 2) the green PAR effect is probably found under intense irridiance like an HID (high PPFD) which is not found under most LEDs at the distances they are hung from the canopy (regardless of LED wattage, distance has a greater effect on PPFD then wattage). Thus with LEDs I don't think green is all the helpful, but I am not sure.

RE: custom setups:
I wouldn't think so, as they are not cost effective for the avage grower, nor available to the average grower. But, for the sake of argument, sure, what difference would it make? You still can't make bright white light with LEDs and have an even SPD over the canopy (i.e., some canopy areas will get more blue than red; this would not be the case, or as extremely the case with HID in good reflector without a protective glass.

I already provided all the proven scientific theory most any agenda-less person needs...

 

[Grat3fulh3ad]

My only agenda is the most kind bud for the least energy cost.

I only wanted mathematical proof that LED arrays can not result in better Pn than HIDs.

I grow with HIDs, where's the agenda?

 

[secondtry]

I have told you over and over and over...
Measuring results is easy... photosynthesis = biomass.

No it does not, it's not that liner. It suggested it and often proves true but not a one-to-one basis. The reason no one sues biomass as a method of quantiation of light stimuli is it is indirect and is influenced by many other facts, Pn on the other hand is direct, immediate, and as noted by another IC member "Avenger" (great post BTW) Pn is a in general a result of specific and rather limited (in number) stimuli. Pn is a good method for quatitation and often used by scientists because it is a central biological function to the plant; thus ideal or peak Pn should allow for other areas like yield and secondary metabolite production to reach ideal or high levels.

Pn (and associated Pn process) is what we should be measuring, not yield.

 

[Grat3fulh3ad]

To cannabis growers resin is more important than equation.
I will go you one better...
If increasing Pn does not result in more efficient growth then it is completely irrelevant to cannabis farmers.

It may not be the perfect measure of photosynthesis but it is the only one that matters to 99.99 percent of growers here... If I can grow more bud per watt with no loss in quality who cares what some rice study or wheat study says?

 

[Grat3fulh3ad]

No it does not, it's not that liner. It suggested it and often proves true but not a one-to-one basis. The reason no one sues biomass as a method of quantiation of light stimuli is it is indirect and is influenced by many other facts, Pn on the other hand is direct, immediate, and as noted by another IC member "Avenger" (great post BTW) Pn is a in general a result of specific and rather limited (in number) stimuli. Pn is a good method for quatitation and often used by scientists because it is a central biological function to the plant; thus ideal or peak Pn should allow for other areas like yield and secondary metabolite production to reach ideal or high levels.

Pn (and associated Pn process) is what we should be measuring, not yield.

In a controlled experiment with identical conditions excepting for light source... what are all these other influencing factors that make biomass so inaccurate?

Is not biomass production the standard by which most cannabis growers compare garden efficiency?

 

[secondtry]

My only agenda is the most kind bud for the least energy cost.

Pulse-start HID (not SunPluse, they suck!!) plus digital ballast = reduced energy with "most kind bud"

Unfortunately, siad pulse-start HID lamps are not avablie, all we have is "probe-start"; but I plan to have some pulse-start lamps manufactured by a German company. You see, that is were my study is all heading too: I design reflectors and HID lamps, among other interests. I am working on pulse-start HID with specific SPD (matching the ASP of cannabis; which I will first create with "reflectance spectroscopy") which when used with digital ballast is the future IMO: less energy used and more PPFD provided according to ASP and the PPFD is more consistent too...all while using a light-mover, high air velocity, cooled-air and no glass shield.

I only wanted mathematical proof that LED arrays can not result in better Pn than HIDs.

I already gave you that, in my own explanations and in those two studies I posted.

HTH

 

[Grat3fulh3ad]

sulphur lights are probably the future of grow lighting anyhow.

 

[Grat3fulh3ad]

I design reflectors and HID lamps, among other interests. I am working on pulse-start HID with specific SPD (matching the ASP of cannabis; which I will first create with "reflectance spectroscopy") which when used with digital ballast is the future IMO: less energy used and more PPFD provided according to ASP and the PPFD is more consistent too...all while using a light-mover, high air velocity, cooled-air and no glass shield.

Aahhhh, there's the agenda....

I misunderstood... I thought you were saying I had an agenda... sorry.

 

[secondtry]

I don't have an agenda, I am not selling them. My only agenda is yours, the best cannabis with least energy.

 

[GreenThumbBumb]

He seemed to want to increase yield, that was his whole reason for the thread. And to increase yield increasing heat won't matter, he needs to increase PPFD and PAR range; hence, he needs HPS to increase yield so yes, I answered his question more thoroughly than you did.

And btw, Pn is the way to quantitate plant response to light stimuli, that and respiration/transpiration.

Aw sorry i missed this, i know its late, and you never even answered his question, lol.

 

[superpedro]

To me it's very simple.

The short version:
The final product of the absorbed light is an energy rich molecule called ATP, it can be used to either assimilate CO2 or, in low heat conditions, some of it will be used directly for heat meaning less growth.

The leaf temperature is dependent on air temperature and IR radiation. LED's need higher air temps than hps, flouros likes it a bit hotter too.

The same goes for night temps. Optimal conditions enables the plant to convert some of the stored carbon from starch to growth instead of heat. This is important if you add CO2 to your grow, and want the full payback!

Low leaf temperatures furthermore makes for slower maturation

IMO There is a lot more yield to be gained from optimal climate than all the hyped additives they try to sell.

 

[Grat3fulh3ad]

IMO There is a lot more yield to be gained from optimal climate than all the hyped additives they try to sell.

q f t