Re: [Aroid-l] LED lighting (was aroid recommendations)

From: bonaventure at optonline.net on 2009.01.26 at 18:50:13 =3CDIV=3EHi Steve=2C=3C/DIV=3E=3CDIV=3EThese are approximately the wavelengths that I have=2E In my experience some flourescent=26nbsp=3Bbulb plant lights give off a =22purple=22 light (actually 2 peaks=2C 1 in red and 1 in blue) and under them=2C bright as they may be=2C =26nbsp=3Bplant leaves look BLACK=2E I took this as a sign of efficiency=2E These plant tubes were expensive (not as much as LEDs) but did invariably weaken and die out (unlike LED supposed 100=2C000 hour life) and produce heat=2C unlike LEDs=2E Plants did grow well under them for me though=2E We=27ll see how this works=2E Found interesting links on youtube=2C and=2C though not my inclinations=2C setups and information on cannabis=2Ecom=2E=3C/DIV=3E=3CDIV=3EBonaventure=3C/DIV=3E=3CDIV=3E=26nbsp=3B=3C/DIV=3E=3CDIV=3E=26gt=3B=26gt=3B=26gt=3B=26gt=3B=26gt=3B=26gt=3B=26gt=3B=26gt=3B=26gt=3B=26gt=3B=26gt=3B=26gt=3B=26gt=3B=26gt=3B=26gt=3B=26gt=3B=26gt=3B=26gt=3B=26gt=3B=26gt=3B=26gt=3B=26gt=3B=26gt=3B=26gt=3B=26gt=3B=26gt=3B=26gt=3B=26gt=3B=26gt=3B=26gt=3B=26gt=3B=26gt=3B=26gt=3B=26gt=3B=26gt=3B=3C/DIV=3E=3CDIV=3E=3CFONT face=3DArial=3EHi Bonaventure=2C=3CBR=3E=3CBR=3EPAR is just the acronym for =22photosynthetically=26nbsp=3Bactive radiation=22=2C i=2Ee=2E=2C =3CBR=3Ethat in the frequency ranges which plants actually use (400-700 nm or so)=2E=3CBR=3E=3CBR=3ESince LEDs are by nature monochromatic (the =22white=22 ones either use =3CBR=3Emultiple colors together=2C or have a phosphor which re-emits broader =3CBR=3Espectrum light)=2C plant growers very quickly hit on the idea of using only =3CBR=3ELEDs which emit near the peak absorption frequencies of the two higher =3CBR=3Eplant chlorophylls=26nbsp=3B(430-455 nm in the blue=2C 640-665 in the red)=2E=3CBR=3E=3CBR=3EIt=27s not clear to me whether that really improves things or not=2C since my =3CBR=3Eunderstanding was that other pigments present in leaves=2C acting with =3CBR=3Echlorophyll=2C tended to spread out the range of frequencies which plants =3CBR=3Ecould use across that 400-700 nm range=2E So I bought a PAR meter=2C even =3CBR=3Ethough it wasn=27t cheap and it uses funky non-SI=26nbsp=3Bunits (microeinsteins=2C or =3CBR=3Eoften microeinsteins/meter squared/second) that have to be converted to =3CBR=3Eand from *everything*=2E=3CBR=3E=3CBR=3EI don=27t know if I=27ve really learned much or not (except that in the end=2C =3CBR=3Eyou still have to just try things and see if the plants grow well)=2C but I =3CBR=3Ecan sling a lot more numbers now when I talk about it!=3CBR=3E=3CBR=3ESteve=3C/FONT=3E=3CBR=3E=3C/DIV=3E--Boundary_(ID_Woi30uibOAMmoQkxaUbYwQ)----===============1288094192933910714==

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