Led guys chime in

Horselover fat

Well-Known Member
The burlple lights are just outdated and trash when it comes to power and photons to the plant. The spectrum is incomplete by alot as plants use green and everything in between. It might not be much but the rounded out spectrum will out do purple lights anyday in every way.
The kind they sell are outdated and shit, but a blurple can be much more efficient than white. I'm not at all convinced white spectrum would out do purple lights anyday in every way.
 

ANC

Well-Known Member
The reason white LEDs kicks arse is because they are the cheapest source of green light
 

Lordhooha

Well-Known Member
[Citation needed]
Use of green light Green light is definitely required for a rich and healthy light spectrum, missing it out reduces growth and yield, as plants at light saturation would not benefit from the additional energy. Plants also use green light to set their circadian rhythm through phytochrome, cryptochrome and heliochrome, meaning that it is an essential component of plant growth control. At excite we include white LEDs that emit a full spectrum with plenty of green presence, this allows the high PPFD to deliver more growth at levels of saturation that any other type of light that misses green out.

NASA ran tests on growlights and found that a full spectrum of red-blue-green produced more dry mass of crop than purely red-blue, indicating green light’s ability to deliver yields. This was found to be because the plant was already saturated with red and blue light; therefore, a balance including green was more efficient in carbon fixation in photosynthesis. This agrees with McCree’s 1972 study that found a heavy showing of green in a mixed spectrum to produce the most photosynthetic activity.

Broad spectrum lighting – often referred to as full spectrum lighting, means the complete spectrum of light given by sunlight. This means wavelengths of broad spectrum lighting include the 380nm-740nm range (which we see as color) plus invisible wavelengths too, like infrared and ultraviolet. One advantage of LED grow lights is they can be set up to produce certain wavelengths for specified periods during the day or night. This makes it ideal for plants because growers can isolate specific spectrum colors depending on crops and growing conditions. Full spectrum lighting can also speed up or slow growth rate, enhance root development, improve nutrition and color etc.
 

Horselover fat

Well-Known Member
NASA ran tests on growlights and found that a full spectrum of red-blue-green produced more dry mass of crop than purely red-blue, indicating green light’s ability to deliver yields. This was found to be because the plant was already saturated with red and blue light; therefore, a balance including green was more efficient in carbon fixation in photosynthesis.
Interesting, but the nasa test was done with lettuce and rgb monos outproduced white light in the test. Meanwhile Bugbee found no difference in cannabis yield between blurple and white.
 

Lordhooha

Well-Known Member
Interesting, but the nasa test was done with lettuce and rgb monos outproduced white light in the test. Meanwhile Bugbee found no difference in cannabis yield between blurple and white.
This is from 2020

For people who love to grow indoor plants, there are always continuous debates on the best grow light that gets the best results for growth. One of the most recent debates is the difference between effect of white LED lights and red & blue LED lights on indoor plant growth.


We have test these two different LED grow Lights and found that tomato yields increased 12 to 16% when using white LED lights, the results were probably due to the white LEDs that contained more than 50% of green light characterized by high penetration into the canopy.


Second test we observed lettuce grown by using white Led and red&blue grow light separately. The result shows soluble sugar and nitrate contents in the lettuce grown with added white spectrum was significantly higher and lower, respectively. We also observed lettuce under white Led grow light has higher shoot and root fresh and dry weights as well as higher crispness, sweetness, and better plant shape.
 

Horselover fat

Well-Known Member
This is from 2020

For people who love to grow indoor plants, there are always continuous debates on the best grow light that gets the best results for growth. One of the most recent debates is the difference between effect of white LED lights and red & blue LED lights on indoor plant growth.


We have test these two different LED grow Lights and found that tomato yields increased 12 to 16% when using white LED lights, the results were probably due to the white LEDs that contained more than 50% of green light characterized by high penetration into the canopy.


Second test we observed lettuce grown by using white Led and red&blue grow light separately. The result shows soluble sugar and nitrate contents in the lettuce grown with added white spectrum was significantly higher and lower, respectively. We also observed lettuce under white Led grow light has higher shoot and root fresh and dry weights as well as higher crispness, sweetness, and better plant shape.
That seems to be marketting material from a led manufacturer. I found no info on their experiment.

I really do wonder how much of a difference there is. It's a moot point anyhow, because a good blurple is so expensive to build it makes no sense really.
 

PJ Diaz

Well-Known Member
I could see a quality blurple fixtures, built with high intensity diodes, being better for greenhouse supplemental light situations, where there is already ample green spectrum coming from the sun.
 

Horselover fat

Well-Known Member
I could see a quality blurple fixtures, built with high intensity diodes, being better for greenhouse supplemental light situations, where there is already ample green spectrum coming from the sun.
Those are around. Slim designs so they don't block the sun. I can't remember off hand if they have a higher efficacy than than modern whites though.
 

PJ Diaz

Well-Known Member
Those are around. Slim designs so they don't block the sun. I can't remember off hand if they have a higher efficacy than than modern whites though.
I think the newer diodes do have better efficiency than while, at least the red diodes do. Not sure if that has to do with their wider wavelength or what. I haven't really followed blurple science too much tbh. It seems that was what the Lumigro pro fixtures were intended for, but they are way outdated by now. I know of a local greenhouse which still has a bunch of Lumigrow e650's up in their greenhouse, but they are slowly failing. I'm gonna get my hands ahold of one of them, and see what sort of driver is in them, and see if they can be easily retrofitted or not.
 
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