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High power Light Emitting Diode technology has improved tremendously in the past few months, in my opinion offering great potential for micro growers. Emitter luminous output and efficiency have near doubled since much of the LED posting around here, and likely will improve even more by the time current units reach the grow light market. Cost is dropping rapidly too. Any other DIY electronic types here building your own setups or considering it? Looking for serious discussion of LED growing, photosynthetic spectrum, optics, wiring, where to buy, etc.
To begin with, why do so many LED grows reportedly fall short of HPS or CFL? Several possible reasons come to mind:
* misunderstanding of lumens, PAR, radiant flux, mcd, etc. how much usable light are plants actually getting? marketing hype may vastly overstate it.
* photosynthetic action spectrum and LED wavelengths - what quality of light are plants getting? it seems that more experimentation is needed in this area for cannabis, including UV and IR effects.
* less efficient older LED's - comparing watts alone hardly tells actual light output.
* cost - grower may tend to use less light than if cost were not a factor.
Much to consider in designing a LED setup; power supply and drivers, what wavelengths and how much of each, thermal management, which manufacturers... anyway I plan to start one soon and welcome any input. LedEngin has high power 660 nm deep reds, apparently hard to find until now. Blue and royal blue K2's and such are widely available, as are whites. I like the idea of running a little white in the mix, since they have a blue peak to help keep internodes short in flower and also have a wide band elsewhere to cover accessory pigments' possible needs:
http://icmag.com/ic/album.php?albumid=187&pictureid=1044
Eye safety... most blue and white high power emitters come with a warning, but worth repeating here: do not stare directly into them... 'nuf said.
Going with almost all blue and royal blue for veg, not sure yet what ratio of blue to red and deep red for flower. And does UV really make a worthwhile difference in resin production? High power 400 nm are available cheap now, but somewhere I read that 320 nm UVB is what supposedly counts. Open to suggestions
To begin with, why do so many LED grows reportedly fall short of HPS or CFL? Several possible reasons come to mind:
* misunderstanding of lumens, PAR, radiant flux, mcd, etc. how much usable light are plants actually getting? marketing hype may vastly overstate it.
* photosynthetic action spectrum and LED wavelengths - what quality of light are plants getting? it seems that more experimentation is needed in this area for cannabis, including UV and IR effects.
* less efficient older LED's - comparing watts alone hardly tells actual light output.
* cost - grower may tend to use less light than if cost were not a factor.
Much to consider in designing a LED setup; power supply and drivers, what wavelengths and how much of each, thermal management, which manufacturers... anyway I plan to start one soon and welcome any input. LedEngin has high power 660 nm deep reds, apparently hard to find until now. Blue and royal blue K2's and such are widely available, as are whites. I like the idea of running a little white in the mix, since they have a blue peak to help keep internodes short in flower and also have a wide band elsewhere to cover accessory pigments' possible needs:
http://icmag.com/ic/album.php?albumid=187&pictureid=1044
Eye safety... most blue and white high power emitters come with a warning, but worth repeating here: do not stare directly into them... 'nuf said.
Going with almost all blue and royal blue for veg, not sure yet what ratio of blue to red and deep red for flower. And does UV really make a worthwhile difference in resin production? High power 400 nm are available cheap now, but somewhere I read that 320 nm UVB is what supposedly counts. Open to suggestions
