I get bored a lot and I know lots about leds and their role in photosythesis, especially as it pertains to the indoor cultivation of our beloved cannabis. Thought I'd introduce myself and start talking shop.
Anyway, these days, the right LED should cover about five different spectrums, excluding any white filler. infrared and UV radiation have both proven to beneficial and as the case my be, essential, in order for the plants to produce the full range of possible cannabinoids and terpenes. We're not just trying to keep the plants alive, during flowering we should bring out the best that the plant has to offer.
Anyway, I'm also technologically savvy. I know modern LED lights should have advanced secondary optics, heavy duty heat sinks (if you want years out of your light) and if you're lucky a microcontroller to prolong the life of your LEDs.
Allow me to explain that last part. That's what separates a light like a GN ms0004 and my LED. I posted a review of it a while ago, probably linked in this thread. The LEDs are all powered directly from a voltage converter. With a microcontroller you have the option of controlling your LEDs with pulse width modulation.
PWM is one of the secrets behind the success of Grow Northern lights. instead of always being on, it switches the voltage to the LED's from 3 to 0 and back to three in millionths of a second, basically flickering them as fast as the programming and microcontroller allows.
This is huge. That means they can run cooler, since they only produce heat (which kills any semi conductor) when they're on. So by blinking the lights, you use less energy, your LEDs run cooler, and I believe there's a second part to the story.
(i get off on tangets)
I think I remember reading somewhere that leaves can only absorb a certain amount of radiation per second or minute or something. Don't quote me on that, but I might have read something to that effect. The point is, most 3w LEDs produce ample PAR even when controlled via PWM (i.e. being off for part of the duty cycle). So this is definitely the tech we'll be growing with.
Back to the optics. You'll want the most up to date, futuristic, lenses you can buy, but you're pretty much stuck with three options.
60 degrees.
90 degrees.
and 120 degrees.
At the end of the day, it really depends on the canopy you'll be working with during flowering. Veg lights are different. But if you'll only be using one for the grow, i'd get a 90* - it's sort of the meeting point between photon penetration through the vegetation and coverage area, just in case square footage is a concern.
The best heat sinks I've ever seen on a grow light are vapor condensation pads on Kessil grow and aquarium lights. Basically it's a hollow metal case with a liquid inside that absorbs heat and evaporates and condenses on the other side of the pad, where there's a big dc fan circulating air. I have no doubt, based on the reputation of the company that they've developed an unmatched heat management system. Dunno if GN uses an auto/off feature just in case the unit over heats, but I do know California Light Works has that built in. Just so it doesn't cook itself.
What you need to understand is, each LED consumes 3w of power. It turns most of that into light. It's nearly the most efficient way to do that - but since it concentrates all of it's energy on one small chunk of luminescent phosphors, it tends to heat it rather quickly, even at low voltages. So a good heat sink is a must. I don't care if you're unit feels like it's running cool, those diodes are small, and on their scale, you'd hardly know if they were over heating till they burn out on you, unless you have an infrared thermometer... point that at your heatsink or the actual diode if you want an accurate reading of the semiconductor surface temp.
So all this stuff, the right spectral profile, highly efficient optics, a proper heat management system and PWM drivers... all of that can come together to create a really dependable grow light that you'll use season after season. Just gotta know what to look for.
Anyway, that's my write up - PM me with questions. I'm a timely responder.
