LED Flood Lights

[Setter]

I'm going to use LED Flood Lights for supplemental lighting during the winter. Does it make any difference if the flood light is 3000K or 5000K?

[Subrosa]

5000K is closer to natural sunlight and provide a better appearance imo, and all other things being equal would be my choice. Either will grow plants.

[estación seca]

The K number refers to how the light looks to the human eye. Lower numbers are more yellowish, higher numbers more bluish. It has nothing to do with how well the lamp might work for growing plants.

[Dollythehun]

Are you near an IKEA? They have a great LED plant/flood bulb. Vaxter.

[Nexogen]

In the figure below you can see the spectrum difference (approximately) between 3000K and 5000K. 5000K (Color Temperature) contains a lot of blue (420 - 470nm), very good for vegetative but not too red (620 - 680nm) which will lead to a lack of flowers. In the case of the 5000K LED, the spectrum is different compared to the 5000K T5 fluorescent tube.

[estación seca]

Originally Posted by Nexogen

In the figure below you can see the spectrum difference (approximately) between 3000K and 5000K. 5000K (Color Temperature) contains a lot of blue (420 - 470nm), very good for vegetative but not too red (620 - 680nm) which will lead to a lack of flowers. In the case of the 5000K LED, the spectrum is different compared to the 5000K T5 fluorescent tube.

Spectrum of what? The graph is not labeled. Color temperature in degrees K is completely meaningless for growing plants in all circumstances. It is an invented number describing how the color looks to the human eye. It has no relation to the real wavelengths emitted by a lamp.

The graph above shows a continuous spectrum, which might be emitted by a star or an incandescent lamp, not an LED lamp.

LEDs consist of assemblages of individual emitters, each of which emits at one, 1, wavelength. There is no spectrum curve. It is a bar graph. Various colors are combined so people think it looks white. The color temperature is a guess at how closely this white color compares to the sun, as viewed by a human eye. Color temperature in degrees K provides no information about the spectrum emitted by a lamp.

The only way to find out what a given LED assembly on the market emits is to test it, and measure the amount of light emitted at each wavelength. Only after doing this could one make predictions about whether a lamp is useful for plants.

[Nexogen]

In the figure below, see how a led is built to see its white light. In the discussion here is "LED Flood Lights" (if you know what it is?).

[estación seca]

That's one particular LED. There are many different LEDs sold. Each will have different wavelength emissions.

[Nexogen]

Of course there are different LEDs on the market. In the figure I exposed, I showed approximately the spectrum that emits a Flood Lights LED. There is no secret, LEDs in this category (that is, cheap) use the same technology, only the quality of the phosphor differs.
Accidentally, the White LED spectrum can also be used for photosynthesis.
PS: In this chapter (the influence of light spectrum in plant growth) there is much to say, but I do not want to talk.

[Ray]

Originally Posted by estación seca

Spectrum of what? The graph is not labeled. Color temperature in degrees K is completely meaningless for growing plants in all circumstances. It is an invented number describing how the color looks to the human eye. It has no relation to the real wavelengths emitted by a lamp.

Actually, that's not quite true.

The color temperature in degrees Kelvin for incandescent light sources - the sun, flames, filament lamps, arc lamps and HID's - tells you what the spectrum truly is. It is when you come to non-incandescent bulbs like fluorescents and LED's that the "color temperature" is a correlated or corrected color temperature - correlated to how it looks to the human eye.