I assure you I am very familiar with diodes myself, from PN junctions all the way to direct band-gap semiconductors such as gallium arsenide.
now, I've seen the plant-light spectrum sensitivity charts, and I know all about PAR , and yada yada yada.
You say 700wLED > 1500w Mixed HID.
We could go tit for tat, stat for stat all day long, and get nowhere.
For me it always comes down to the empirical evidence.
I have in fact seen a journal that i would trust that pulled over 2.5 g/w from a 600wHPS. it wrapped the plants around the light to take advantage of the radial distribution from the source, but to me that's just optimizing the system to the light. perfectly legit to compare to.
Have you seen a reputable LED journal where someone topped that?
With LED's, you're exchanging intensity for focused spectrum.
One uncertainty I have with LED is if the very focused spectrums that are being used are as beneficial as it would seem on paper. Plants have evolved over millenia adapting to the spectrum of the sun. . . this is why it is more efficient in certain wavelengths, namely the weaker wavelengths of the sun. LED grow lights assume concentrating the light down to only the most sensitive bands will greatly improve efficiency. I am not convinced that this is true. The sun's spectrum is continuous. (except for very very small bands according to composition, hydrogen, helium, etc) MH and HPS spectrum's are also continuous, albeit perhaps not tuned for optimal PAR absorption, LED grow lights however have no breadth to their spectrum. 5 bands? Where is the research that shows this is actually beneficial?
I mean, I know they work, and 1g/w is very respectable, but are they 2x more efficient like you say, or 3x or 4x like cammie says, or 6x or 7x like i see on some advertisements?
empirical evidence bro. damn that burden of proof. lol.
I know, i just keep typing, sorrybut,
there are a lot of unknowns as well that people don't talk about, like Relative Flux vs. Junction Temperature. . . a Cree Xlamp LED with 100% Relative Flux at 25*C (room temp) only runs at 70% Relative Luminous Flux @ 150*Celsius.
also, Overall luminous efficiency is actually not all that impressive for LED's. . . it's only the ability to focus the spectrum that makes them possibly more efficient, enhancing their PAR rating. but in efficacy (lm/w) HID's and T5ho's are both more efficient.
anyways, sorry to ramble on after a smoke. . . if you want to discuss more, we should do it in the LED forum. even though maxx is not around often, this thread should be about the Volks. sorry maxx for ramblin.
And as you mentioned plants have evolved to work with the sun and considering there are now many strains of cannabis plants that have been propogated and bred entirely under Metal Halide and Hps lights I kinda think strains like that while only 20 years old for an agressive breeder that could be quite easily 40 generations of a plants entire evolution under HID lighting.
So cool these wheels are
TorturedSoul said:
