The Basics Of Plant Lighting

periwinkle thumb said:
I broke down.... to go along with my multiple, single cfl's I'm getting the dirt genius 240W LED veg light n the 240W flowering.
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That has to one of the worst spectra used on an LED light I have ever seen. Likewise, the flower and veg models state they have the exact same ratio of diodes. If they do have 850nm IR diodes... they are 100% useless for plant growth.
 
thanks for the response... :D

in the vegetative range:
theres an action peak at about 430nm which also corresponds with the chlor A absorption peak; however, at about 460nm theres a greater chlor B absorption peak with a smaller action peak... i understand the importance of hitting multiple receptors, but which peak - 430 or 460nm - would you emphasize?
 
thanks Icemud that was great info. I am now wondering if mixing an enhance red HPS with the CMH would be an added benefit. The HPS does have a strong spike in the yellow (585 to 595 nm), however, that seems to be in the range that has no photoreptors. Finally, can anyone comment on vertical hoods vs. horizontal hoods (specifically, is the hype about the OG vertical pan out and perhaps seeing as the CMH bulb I am using are open rated would an umbrella type reflector be as effective. receptors
Icemud said:
Here is the video of the test of Par values for CMH, HPS, and led.
[video=youtube_share;yVMbxqddkFU]
[/video]
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https://advancedtechlighting.com/img/cdmvshps.JPG

I also noticed that the test was using the new 315 and the 400cmh retrofit bulbs have an even stronger relative energy in the 400nm range and the 600nm range. Sorry, I tried to post image but was unable to, my computer skills lack a bit:cheesygrinsmiley:
 
The following is the peaks for Chlorophyll A and B:
Chlorophyll A 430
Chlorophyll A 662
Chlorophyll B 453
Chlorophyll B 642

From a lighting efficiency stand point, it is more effective to use a 455 royal blue. The peak of (most) LEDs is +-10nm. When using 455nm royal blues you get 90% of your radient flux in the wavelengths of 445-465nm give or take depending on the binning. In doing so you also hit other photo-receptors like: Alpha Carotene, Beta Carotene, Capsorubin, Cryptoxanthol, Flavin, Lutein, Lycopene, Zeaxanthin, and Zeta Carotene to name a few. Likewise, you can use a combination of warm and cool white diodes to hit a fair number of wavelengths. Not at a high intensity but enough to allow the reactions we are looking for to happen within the plant.

Eldest, they do not make diodes in most of the wavelengths you have mentioned. The simple answer is yes, you are missing most of the accessory pigments. That will grow some killer lettuce and basil tho.
 
direless said:
thanks Icemud that was great info. I am now wondering if mixing an enhance red HPS with the CMH would be an added benefit. The HPS does have a strong spike in the yellow (585 to 595 nm), however, that seems to be in the range that has no photoreptors. Finally, can anyone comment on vertical hoods vs. horizontal hoods (specifically, is the hype about the OG vertical pan out and perhaps seeing as the CMH bulb I am using are open rated would an umbrella type reflector be as effective. receptors
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I ran a CMH and HPS combo in my flowering tent for about 5 grows, and had phenomenal results! I would keep running that combo but the high electric bills recently made me switch over to LED. My last grow I ran LED/CMH combo and achieved my best harvest yet (many other factors besides lights also helped with this) but overall I definitely have to say the LED/CMH combo produced the frostiest, most flavorful nugs to date yet. Now I currently am running completely LED, I haven't harvested yet to comment, but by the way things are looking, even healthier than before! Mixing up spectrum is never a bad idea, as long as they key goal is better PAR value and better full spectrum lighting. :)

There actually are photoreceptors in the yellow region as well. Phycoetherin for example is at 495 and 566nm. This would be why hosebomber suggested adding a few white's in there to cover these areas. Warm white and cool white have heavy blue around 460, drop around 500nm, and then have a nice full yellow/orange/red end. Perfect for filling in the gaps :)

I can't comment on horizontal vs vertical because I have only used horizontal hoods, however I did want to make this point...If you plan on using CMH bulbs...These bulbs can only be used EITHER horizontally or vertically but NOT BOTH!! Each bulb has a code either HOR or VER which will describe how that bulb should be run, so make sure if you order CMH bulbs you order the right one. Also another warning about CMH bulbs...They are only designed to run on HPS MAGNETIC BALLASTS... They will not run on electronic/digital ballasts!!
 
so the light ive ordered is a hunk really then.. shit...

is that ok
630nm Red: 660nm Deep Red: 460nm Blue: 440nm UV: 740NM IR: 3000k Warm White=60: 12: 24: 6: 6: 12

as that would be just the normal light but i thought id be smart and try make my own to this standard..
1. 439NM--1pcs
2. 469NM--2pcs
BLUE

3. 642NM--6pcs
4. 667NM---6pcs
RED

5. 483NM--2pcs
6. 740NM--1pcs

and your saying ill grow a killer lettuce lol fuck me...

what should i do i really need some advice man should i just stick to the standard setttings...i also have options to add

We are able to custom make the light per customers' request, we can make 90W, 120W, 300W, 600W
Red 620nm-680nm
Blue 440nm-470nm
Orange 600nm-610nm
Yellow 580nm-590nm
Warm white2700K-4500K, white6000K-6500K, cold white7500K-12000K
Violet 380nm-420nm, Infrared 700nm-850nm LEDs

please get back to me n thanks so much dude, i already paid the people for my lettuce light and im freaking out i can tell them to change it if need be...:thumb:
 
an electrician friend of mine is going to build me a grow light... apparently, his hardware supplier can provide 430, 450 and 470 LED's... i also have access to an Ocean Optics USB4000 Miniature Fiber Optic Spectrometer, so i will be able to clearly determine their real nm... i have 12 spots assigned to vegetative range, so which ratio of 430, 450, 470 would you suggest... 6 : 3 : 3 OR 3 : 6 : 3 OR 3 : 3 : 6 OR another?
 
Go back to the beginning of this thread and read about the guy doing the 132 piece 3W and 5W setup... All the leds you need and don't need, who makes them, and where to buy them...
 
My question is ... how much energy does that plant use for each peak during each growth cycle stage?

Hosebomber said:
The following is the peaks for Chlorophyll A and B:
Chlorophyll A 430
Chlorophyll A 662
Chlorophyll B 453
Chlorophyll B 642

From a lighting efficiency stand point, it is more effective to use a 455 royal blue. The peak of (most) LEDs is +-10nm. When using 455nm royal blues you get 90% of your radient flux in the wavelengths of 445-465nm give or take depending on the binning. In doing so you also hit other photo-receptors like: Alpha Carotene, Beta Carotene, Capsorubin, Cryptoxanthol, Flavin, Lutein, Lycopene, Zeaxanthin, and Zeta Carotene to name a few. Likewise, you can use a combination of warm and cool white diodes to hit a fair number of wavelengths. Not at a high intensity but enough to allow the reactions we are looking for to happen within the plant.

Eldest, they do not make diodes in most of the wavelengths you have mentioned. The simple answer is yes, you are missing most of the accessory pigments. That will grow some killer lettuce and basil tho.
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I know you pulled all of that directly from some company website, but there is some misinformation in there. Most notably, it states the peak wavelengths for Chlorophyll A and B then states synthesis peaks at 435 and 445 for blue and 640 and 675 for red. The peaks stated directly above that are correct. Secondly (and most important) is the addition of UV:B. There is no hard scientific data that proves UV:B adds to potency. I will agree that it does to some degree but there is no scientific data. At the same time, I can verify that adding more than 7% total light as UV:B WILL give you plant morphology and not in a good way. Likewise, Violaxanthin is a byproduct of Zeaxanthin which has 3 peak wavelengths at 423 451 and 483. There are no carotenoids with a peak above 500nm that I am currently aware of.
 
Hosebomber said:
Secondly (and most important) is the addition of UV:B. There is no hard scientific data that proves UV:B adds to potency. I will agree that it does to some degree but there is no scientific data. At the same time, I can verify that adding more than 7% total light as UV:B WILL give you plant morphology and not in a good way.
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What kind of plant morphology? During the last half of flowering on my last grow, I used 104 watts of 10% UVB CFLs, out of a total 522 watts of CFLs used during flowering, and I did not notice any unusual or undesirable changes in my ladies.
 
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