Led Tutorial From A Global Pro
I'm going to make a short post here explaining the basics you need to know in order to get the most out of any LED-based grow. This guide is meant for all, even experienced HID growers that have never used LEDs.
First off, you need to know proper emission spectra. Not just any blend of LEDs will work, and by all means avoid white LED panels. A panel with a few white LEDs for providing usable observation light is fine, but you don't want too many, just enough to see the full color spectrum (I'm used to watching plants under pure blue and red so I don't need the added green to help with details.) The best range of blue is from 420nm-470nm, and the best red range is from 640nm-670nm. It's entirely up to you which wavelengths you use in those ranges - I'm not divulging my proprietary blend, sorry, I do have a business to run.I will tell you this, though - most companies have WAY TOO MUCH RED AND ORANGE IN THEIR PANELS AND TUBES. Completely out of proportion compared to natural sunlight hitting the ground at sea level AT ANY GIVEN SEASON. If you build your own array, please keep that in mind. If you buy pre-made panels, try to get the best blending you possibly can. I'm working on making veg and bloom specific tubes and panels available, and general-purpose as well.
Secondly, you need to take into account wattage and emission angle of the diode, at the same time. A 1 watt LED with a 120 degree emission angle will only be good for about half a meter height at most (about 1 and 2/3 feet for USA people.) A 1 watt LED with a 45 degree emission angle will not spread out as much but provide better overall penetration, but you will need more of them to cover an equivalent area. Depending upon your LED panel form factor, you may need to mount your panels or tubes differently. Tubes especially, with wide-angle diodes, work best either in an array configuration, or out to the sides of the plants, for better depth of penetration. Narrower-angle LEDs will work just fine mounted directly overhead, in most typical applications, with the exception of LED grow spotlights. You might wish to find a circular mover that will let you put the spot outside the plant, angled down upon it, and rotate it around the plant for optimum efficiency. I've seen a 15-watt LED grow spotlight pump a fat 1.5oz from a single plant done this way. Of course, this is all dependent upon what you're growing, and how you're growing it.
Third, ignore anything that uses diodes under 1W rated power. You see 9 watt grow bulbs with 80+ LEDs in them - they're good for tiny herbs, nothing more. They cannot obtain any usable penetration.
Fourth, consider reflective material, especially when using wide-angle LEDs. Your best bet is going to be either mylar or polished aluminium sheeting attached to the wall (not foil, though it does work.) Also consider investing in a light mover (if you're not using fluorescent-style LED tubes, anyways,) as this will increase your coverage area - plants don't need full *direct* light constantly, this is why light movers work.
Fifth, please ignore all the "90w LED = 400w HPS" nonsense. Here's what really matters - will 400w of LED beat 400w HPS, watt-for-watt, yield for yield?? That answer is yes, and that's what is important. How much LESS light you require is entirely up to your methods and level of skill. Bear in mind many of those 90w=400w claims are done using light movers and don't take into account those parts of the electrical system.
Sixth, LEDS WILL GET HOT, DO NOT FOOL YOURSELF. The typical surface temperature of a 1w diode at full power for one second can get hot enough to melt the solder joints, depending upon the diode. Even my 10w 10-LED T8-factor tubes require a HUGE ALUMINIUM HEATSINK to avoid needing fans, and after an hour of operation they're a bit warmer than my hands. See pics of them at http://ledkitsune.livejournal.com along with a journal chronicling a grow of African Basil. The more power you put into lights, the more heat you're going to generate. That's just thermodynamics, we can't get around it, only circumvent it with passive or active cooling methods. *BUT* 400w of LED won't be as hot as even a 100w HPS, guaranteed.
Seventh, please bear in mind that eye exposure to direct blue light or intense light of any wavelength has been shown to aggravate or worsen cases of macular degeneration - ALWAYS WEAR PROTECTION AROUND ANY GROW LIGHT, ESPECIALLY TARGETED-SPECTRUM LIGHTING SUCH AS LED.
Eighth, do not pay attention to lumen ratings. There are some studies out that say green is just as effective as red for inducing photosynthesis, this is not the case for the majority of *TERRESTRIAL* plants. Mostly marine plants use green and yellow-orange light in photosynthesis, like algae, and kelp/seaweed. Most manufacturers are not going to give you a PPFD spec, so you're going to either need your own quantum meter, or a color-specific incident power meter to judge LED output. You could use your eyes, but TAKE HEED OF THE WARNING IN THE ABOVE PARAGRAPH.
Ninth, LEDs have a burn-in time, like most other lamps. Typical burn-in for LEDs is running nominal voltage and maximum rated current for a full 200+ hours nonstop. Good LED suppliers/panel manufacturers will do this, cheap ones skip this test so they initially appear ULTRABRIGHT but then they dim down to their nominal output, or even just burn-out totally, fooling customers.on them.
Tenth, and likely the final spot - they're expensive and you should know the reason behind the cost. It's not because it is a new technology. The cost comes because of the lifespan of the LED and warranty; 5-7 years is a LOOOOOONG time to wait for possible repeat business, and having to replace a panel or unit that fails halfway trough the warranty period is going to be costly for the manufacturer, especially if they're not a local provider for you. This is the same reason you don't find induction lamps used very often in grow rooms, the cost incurred by the benefits of the technology. I am working with partners in the UK, USA, and China to bring the cost of these lamps down.
Oh, perhaps I should give you a list of LED manufacturers and panel manufacturers so you don't get lost trying to find good stuff, eh? I'l see if I can't include some local UK stuff as well.
LED Diodes and Drivers:
http://www.cree.com/
http://www.luxeonstar.com/
http://www.kingbright.com/
http://www.philipslumileds.com/
LED Panel Makers: (I'm not going to sort thru alibaba.com)
http://www.ecoledlights-uk.com/servlet/StoreFront <---- DISCLAIMER: This is my current UK partner providing me with my prototype LED tubes and panels. Tell him Alex sent you, he'll work out a great price for you. I get no money for this, just FYI. Giving a good tip to those in the UK, that's all.
*dont link to grow shops*
*dont link to grow shops*
http://www.solaroasis.com/
http://ledgrowlights.com/
If you have any more questions, please,as away I'll try to answer them as best as I can without violating any of my contracts.
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Originally Posted by hotboxfox
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