Jahulath
Member
Hi all, please don't think me arrogant and I know I am a noob etc. I have spent the last three weeks researching as I design a light I HAVE NEVER GROWN A CANNABIS PLANT. Having spent literally weeks and as I have some free time I figured why not put it out there and see what happens - if I can make one persons life easier by grouping links and quotes then why the hell not eh? This is offered as a humble analysis of information.
I'll not talk about equipment because everyone has strong opinions BUT I have a few observations:
PLANT PHOTOSYNTHESIS:
First thing was light - I found this useful:
http://www.botany.uwc.ac.za/ecotree/photosynthesis/spectrum.htm regarding light and photosynthesis (simple).
http://hyperphysics.phy-astr.gsu.edu/hbase/biology/ligabs.html regarding the same thing but it answers the question "Why aren't plants black" I'll come back to that...
http://www.emc.maricopa.edu/faculty/farabee/biobk/biobookps.html this one really got my tech on as it is a big old lump of science.
Guod mentioned this one http://wc.pima.edu/~bfiero/tucsonecology/plants/plants_photosynthesis.htm
LED SPECTRAL ANALYSIS:
These have a caveat, this analysis was done for aquarium research so they will be less bothered about the redder parts of the spectrum! http://s919.photobucket.com/albums/ad39/redfishnc/LED TESTING/?start=all has some spectral analysis of common LED brands and http://www.advancedaquarist.com/2012/3/aafeature is also about spectral analysis of LED.
Posted by Stardustsailor, an extremely well read fella!
View attachment 2333949
Comparing these charts to predominant LED types gave me:
Blue 425nm and the ~460nm except that 425nm are basically UV (hmmm have a look at this guy http://www.youtube.com/watch?v=aQPC6oAMK4k it's a worthwhile 17 minutes - UVB is at 280nm to 315nm.)
Then there's the red spectrum so 630nm and the 670nm except that 670nm LED are ass rapingly expensive.
I was far from satisfied.
I watched a video of a Ed Rosenthal talking about his thoughts on LED lights, what he said (slowly - very, very slowly) was that he didn't use them on account of the lack of green light that they produce.
I also watched a rather amusing man as he was very very pissed at his lights because he wasn't growing buds. This guy had some shitty LED panels (and some pretty good ones) and has since sorted out his problem with an extra 1000W of led lights but lets be honest that is not really in the spirit of things.
It is about this point that I started thinking about a correlation:
Why aren't plants black? Why wouldn't led lights let a plant bloom? What the fuck is "Carotene"?
So I went off and did some more research and failed to find anything really useful.
My working theory is that whilst photosynthesis with the chlorophyll A and B is well documented because it's really easy to do these experiments on cress or whatever, less is available about other pigments such as anthocyanin. When you think about it plants can use other colours for light collection, marine plants, starved of the red spectrum by water often use a bright red colour - one specific plant I know produces a butt load of anthocyanin but only when it flowers, it makes the leaves go purple.
It is easy to guess that these other pigments play an extremely important part in the biology of a flowering plant. It's not very efficient to reflect both blue and red in favour of green - like trying to eat around a golf ball in your mouth!
Humans traded speech for the ability to choke to death. The ability to talk, as abstract as that concept may be has done us well. It seems logical to me that trading 100% efficiency in photosynthesis for the ability to make better babies would constitute a very good trade.
So in summary regarding spectrum:
280nm to 425nm is reputed to give more resin/better crystals but it will kill your plants in too higher dose.
460nm is nice and safe, no stress for your plants but no buds.
630nm is nice and safe, no stress for your plants and a chance to bud a bit - notice how little photosynthesis occurs at that point in the curve.
670nm is ridiculously effing expensive but it slams that final curve of both chlorophyll A and B!
Plants it would seem can use 1 or 2 bands of light to grow BUT if they do not have anything to tickle them in the carotenes and up the anthocyanin you are unlikely to get the best plants. UV eh?
Looking at the more recent LED setups to come onto the market this is backed up to the hilt. You will not get a dual spectrum light from any reputable dealer but you will start to get combinations of 460nm, 630nm and various kelvins of white that call themselves "full spectrum" towards the lower end and looking around there are folks here growing with exactly this set up. Of course the better ones are going to cover as much as they can, even the 425nm to a smaller extent.
LED THERMAL MANAGEMENT:
Originally posted by Guod!
Nice vid about LED thermodynamics:
Part 1 http://www.youtube.com/watch?v=Qs1HRvjZRKI&feature=related
Part 2 http://www.youtube.com/watch?v=c1OIjaxiR7E&feature=relmfu
Part 3 http://www.youtube.com/watch?v=HgtrKAqKIIo&feature=relmfu
Part 4 http://www.youtube.com/watch?v=aIS_Eeu3CDI&feature=relmfu
I'll not even pretend to understand all of that, there's a lot of variables to learn about though even if it is essentially an infomercial.
LUMENS AND LIGHT INTENSITY:
Next I'm going to talk about lumen but only for a short while because I find it hella boring.
http://www.ifa.hawaii.edu/~barnes/ASTR110L_S03/inversesquare.html
From my experience of 3d modelling I know that light follows an inverse square law - ~you double the distance and half the light. To translate this into something more useful we can say that 30000 lumen at 24" is the same as ~7500lm at 12" - I'm paraphrasing but it is really that intense! Unfortunately this is in theory so before you get excited about the value of your 3000lm at 6" you have to do all of the maths
I like spread sheets because they do maths for me I am not going to do all the maths. This is a concept to keep in mind however because it evens out the playing field a lot for the likes of CFL lights, sadly the fact that LED will only produce light in one direction means that a simple reflector hood pretty much poops all over them because you end up with "Lumens+(3*Lumens*0.75)" assuming about 75% efficacy with the reflector (95% reflective with a whole lot of variables). Bored now.
BASICS OF ELECTRONICS AND WIRING:
A few links about wiring for good measure:
gives a good written description of wiring led http://white-leds.co.uk/led-wiring-guide.htm
http://white-leds.co.uk/led-wiring-guide.htm is a video talking about wiring LED into a series circuit.
How to solder LIKE A BOSS.
http://www.youtube.com/watch?v=BLfXXRfRIzY http://www.youtube.com/watch?v=I_NU2ruzyc4&feature=related
EXAMPLES OF DIY LAMPS:
http://www.youtube.com/watch?v=3T6rUyp_Z-k Somebody awesome (maybe from this site sorry if is) made a little movie about making a lamp.
http://www.youtube.com/watch?v=2E4avJ7F9QE Here is the same guy with his second project! (If I can make half as clean a job of it hehe).
Hope that was halfway helpful to someone somewhere
I'll not talk about equipment because everyone has strong opinions BUT I have a few observations:
PLANT PHOTOSYNTHESIS:
First thing was light - I found this useful:
http://www.botany.uwc.ac.za/ecotree/photosynthesis/spectrum.htm regarding light and photosynthesis (simple).
http://hyperphysics.phy-astr.gsu.edu/hbase/biology/ligabs.html regarding the same thing but it answers the question "Why aren't plants black" I'll come back to that...
http://www.emc.maricopa.edu/faculty/farabee/biobk/biobookps.html this one really got my tech on as it is a big old lump of science.
Guod mentioned this one http://wc.pima.edu/~bfiero/tucsonecology/plants/plants_photosynthesis.htm
LED SPECTRAL ANALYSIS:
These have a caveat, this analysis was done for aquarium research so they will be less bothered about the redder parts of the spectrum! http://s919.photobucket.com/albums/ad39/redfishnc/LED TESTING/?start=all has some spectral analysis of common LED brands and http://www.advancedaquarist.com/2012/3/aafeature is also about spectral analysis of LED.
Posted by Stardustsailor, an extremely well read fella!
- http://biology.mcgill.ca/Phytotron/L...ets%20text.htm
http://biology.mcgill.ca/Phytotron/L...ger%20text.htm
http://biology.mcgill.ca/Phytotron/L...ger%20text.htm
http://biology.mcgill.ca/Phytotron/L...bee%20text.htm
http://biology.mcgill.ca/Phytotron/L...are%20Text.htm
http://biology.mcgill.ca/Phytotron/L...ing%20text.htm
http://biology.mcgill.ca/Phytotron/L...ext%20only.htm
http://biology.mcgill.ca/Phytotron/L...ula%20text.htm
http://biology.mcgill.ca/Phytotron/L...nes%20text.htm
View attachment 2333949
Comparing these charts to predominant LED types gave me:
Blue 425nm and the ~460nm except that 425nm are basically UV (hmmm have a look at this guy http://www.youtube.com/watch?v=aQPC6oAMK4k it's a worthwhile 17 minutes - UVB is at 280nm to 315nm.)
Then there's the red spectrum so 630nm and the 670nm except that 670nm LED are ass rapingly expensive.
I was far from satisfied.
I watched a video of a Ed Rosenthal talking about his thoughts on LED lights, what he said (slowly - very, very slowly) was that he didn't use them on account of the lack of green light that they produce.
I also watched a rather amusing man as he was very very pissed at his lights because he wasn't growing buds. This guy had some shitty LED panels (and some pretty good ones) and has since sorted out his problem with an extra 1000W of led lights but lets be honest that is not really in the spirit of things.
It is about this point that I started thinking about a correlation:
Why aren't plants black? Why wouldn't led lights let a plant bloom? What the fuck is "Carotene"?
So I went off and did some more research and failed to find anything really useful.
My working theory is that whilst photosynthesis with the chlorophyll A and B is well documented because it's really easy to do these experiments on cress or whatever, less is available about other pigments such as anthocyanin. When you think about it plants can use other colours for light collection, marine plants, starved of the red spectrum by water often use a bright red colour - one specific plant I know produces a butt load of anthocyanin but only when it flowers, it makes the leaves go purple.
It is easy to guess that these other pigments play an extremely important part in the biology of a flowering plant. It's not very efficient to reflect both blue and red in favour of green - like trying to eat around a golf ball in your mouth!
Humans traded speech for the ability to choke to death. The ability to talk, as abstract as that concept may be has done us well. It seems logical to me that trading 100% efficiency in photosynthesis for the ability to make better babies would constitute a very good trade.
So in summary regarding spectrum:
280nm to 425nm is reputed to give more resin/better crystals but it will kill your plants in too higher dose.
460nm is nice and safe, no stress for your plants but no buds.
630nm is nice and safe, no stress for your plants and a chance to bud a bit - notice how little photosynthesis occurs at that point in the curve.
670nm is ridiculously effing expensive but it slams that final curve of both chlorophyll A and B!
Plants it would seem can use 1 or 2 bands of light to grow BUT if they do not have anything to tickle them in the carotenes and up the anthocyanin you are unlikely to get the best plants. UV eh?
Looking at the more recent LED setups to come onto the market this is backed up to the hilt. You will not get a dual spectrum light from any reputable dealer but you will start to get combinations of 460nm, 630nm and various kelvins of white that call themselves "full spectrum" towards the lower end and looking around there are folks here growing with exactly this set up. Of course the better ones are going to cover as much as they can, even the 425nm to a smaller extent.
LED THERMAL MANAGEMENT:
Originally posted by Guod!
Nice vid about LED thermodynamics:
Part 1 http://www.youtube.com/watch?v=Qs1HRvjZRKI&feature=related
Part 2 http://www.youtube.com/watch?v=c1OIjaxiR7E&feature=relmfu
Part 3 http://www.youtube.com/watch?v=HgtrKAqKIIo&feature=relmfu
Part 4 http://www.youtube.com/watch?v=aIS_Eeu3CDI&feature=relmfu
I'll not even pretend to understand all of that, there's a lot of variables to learn about though even if it is essentially an infomercial.
LUMENS AND LIGHT INTENSITY:
Next I'm going to talk about lumen but only for a short while because I find it hella boring.
http://www.ifa.hawaii.edu/~barnes/ASTR110L_S03/inversesquare.html
From my experience of 3d modelling I know that light follows an inverse square law - ~you double the distance and half the light. To translate this into something more useful we can say that 30000 lumen at 24" is the same as ~7500lm at 12" - I'm paraphrasing but it is really that intense! Unfortunately this is in theory so before you get excited about the value of your 3000lm at 6" you have to do all of the maths
I like spread sheets because they do maths for me I am not going to do all the maths. This is a concept to keep in mind however because it evens out the playing field a lot for the likes of CFL lights, sadly the fact that LED will only produce light in one direction means that a simple reflector hood pretty much poops all over them because you end up with "Lumens+(3*Lumens*0.75)" assuming about 75% efficacy with the reflector (95% reflective with a whole lot of variables). Bored now.BASICS OF ELECTRONICS AND WIRING:
A few links about wiring for good measure:
gives a good written description of wiring led http://white-leds.co.uk/led-wiring-guide.htm
http://white-leds.co.uk/led-wiring-guide.htm is a video talking about wiring LED into a series circuit.
How to solder LIKE A BOSS.
http://www.youtube.com/watch?v=BLfXXRfRIzY http://www.youtube.com/watch?v=I_NU2ruzyc4&feature=related
EXAMPLES OF DIY LAMPS:
http://www.youtube.com/watch?v=3T6rUyp_Z-k Somebody awesome (maybe from this site sorry if is) made a little movie about making a lamp.
http://www.youtube.com/watch?v=2E4avJ7F9QE Here is the same guy with his second project! (If I can make half as clean a job of it hehe).
Hope that was halfway helpful to someone somewhere
