Let's talk about colors

Hello everyone,

So what's the deal with color spectra ? There seems to be a debate whether whites are better than reds and blues. Some scientific journals I've looked up mention whites for algae ..but algae is underwater and red is the first color to go even at 5ft so that makes sense. Another recent publication comparing red/blue/white and combinations to cfl concluded that a combination of red/blue/white is best.

From my understanding, whites have a more even distribution but their relative power in the color bands that matter for photosynthesis are not as strong as monochromatic leds. Why do I see a trend in whites instead of reds and blues with white supplements ? Help me understand. Cheers!

Casabonita420 said:

Hello everyone,

So what's the deal with color spectra ? There seems to be a debate whether whites are better than reds and blues. Some scientific journals I've looked up mention whites for algae ..but algae is underwater and red is the first color to go even at 5ft so that makes sense. Another recent publication comparing red/blue/white and combinations to cfl concluded that a combination of red/blue/white is best.

From my understanding, whites have a more even distribution but their relative power in the color bands that matter for photosynthesis are not as strong as monochromatic leds. Why do I see a trend in whites instead of reds and blues with white supplements ? Help me understand. Cheers!

Click to expand...

warm white phosphor based leds are the currently best overall grow/bloom spectrum for cannabis to date.

There are a ton of threads discussing the same. In short, white COBs are blue diodes with phosphor coating. Thus, you can get plenty of blues simply by selecting the desired white color temperature (for example 3500K instead of 2700K). Warm white generally has plenty of red up to the 630nm range. There are some who think that it's a good idea to supplement with 660nm reds.

Thanks for replying, don't want to sound rude or difficult but it doesn't really answer the question.
Whites may have plenty of blue and red but if red and blue is what we want for why not go with red and blue?
I'm trying to understand the logic behind it.

Casabonita420 said:

Thanks for replying, don't want to sound rude or difficult but it doesn't really answer the question.
Whites may have plenty of blue and red but if red and blue is what we want for why not go with red and blue?
I'm trying to understand the logic behind it.

Click to expand...

because the absorption of ch A and B lead to false conclusions under anything close to a production grow light.
pay attention to an actual photosynthetic action response test. ref: mcree bugbee and others.

Use the search engine mate, this topic was discussed a thousand times already.
This paper is a good starting point imo: http://www.inda-gro.com/IG/sites/default/files/pdf/McCree 1972 Revisited.pdf

I Like Colors As A Matter Of Fact I'm Really Fond Of Periwinkle Blue

Casabonita420 said:

Thanks for replying, don't want to sound rude or difficult but it doesn't really answer the question.
Whites may have plenty of blue and red but if red and blue is what we want for why not go with red and blue?
I'm trying to understand the logic behind it.

Click to expand...

I'm not going to get into the red and blue debate, but one of the reasons they are an efficient light source is there are many leds running at a few ma each, which is impossible to do economically with single die packages.

Here is what I mean:




I do think once/if green phosphor catches up we might see mixed colors becoming a thing, maybe the main thing.

Thats a great shot mate!

What matters the most is how much light the plants receive within the the PAR range.

Too much blue will cause damage to the plant while too much red causes undesirable morphological changes. Blue and red also have poor penetration. R+B lamps tend to be used more for very short plants like lettuces that don't rely on shade avoidance to produce their shape.

JorgeGonzales said:

I do think once/if green phosphor catches up we might see mixed colors becoming a thing, maybe the main thing.

Click to expand...

Goggle "lime leds"

is this the gang thread, bitches?

::

There's no doubt that white light contains all spectra and they probably all benefit the photosynthetic process in different degrees. In addition there is recent proof (1) that RBW is better than RB. However I am interested in optimization hence the question of whether RB should be supplemented with W or vice versa.This research (2) established that a ratio of 95/5 R-B spectral balance gave the best growth response but also compared the energy efficiency of the targeted lighting system to that of a untargeted (white) system.
Papers (3) & (4) also seem like an interesting read although more heavy on the scientific jargon ...
Any biologists here care to decode this stuff to plain english for us ?

1) The effects of red, blue, and white light-emitting diodes on the growth, development, and edible quality of hydroponically grown lettuce (Lactuca sativaL. var.capitata) (http://www.sciencedirect.com/science/article/pii/S0304423812004797)

2) Significant reduction in energy for plant-growth lighting in space using targeted LED lighting and spectral manipulation (http://www.sciencedirect.com/science/article/pii/S2214552414000327)

3) Photosynthetic Quantum Yield Dynamics: From Photosystems to Leaves (http://www.plantcell.org/content/24/5/1921.full.pdf+html)

4) Intra-leaf gradients of photoinhibition induced by different color lights: implications for the dual mechanisms of photoinhibition and for the application of conventional chlorophyll fluorometers (http://onlinelibrary.wiley.com/doi/10.1111/j.1469-8137.2011.03669.x/full)