Difference between 6,700K, 10,000K and 18,000K

[DoctaQ]

ive grown plants with 12k pc, but i would not do it again because it looked oddly blue, i have also done 10k and that worked out fine too, the difference between 10 and 6.7k isnt that big of a gap and is mostly up to preference, 10k will look slightly bluer.

18k is a def no go, that high of a color temp should be reserved for reef or reef wannabe

plants use light of certian wavelengths, not the entire 10 or 12k spectrum, however the spectrum tends to dictate what the spectral output graph will look like, in terms of where the peaks of wavelengths will fall, the higher the spectrum the higher the blue peak will be and shorter the other peaks will be, i would also think it will look slightly dimmer to the eye.

 

[dundadundun]

plants use light of certian wavelengths, not the entire 10 or 12k spectrum, however the spectrum tends to dictate what the spectral output graph will look like, in terms of where the peaks of wavelengths will fall, the higher the spectrum the higher the blue peak will be and shorter the other peaks will be, i would also think it will look slightly dimmer to the eye.

i don't completely disagree but this can be misleading to someone who doesn't understand. plants use what we can see... and beyond. it's what they prefer not what they use. for example... the myth that plants cannot use green light at all (henceforth what we see vs what they see since we see green the best) is not true. they just use it to a lesser extent... to a point it's almost useless to rely on.

no the perceived color of a bulb (not spectrum) does not determine the graph, the graph determines the color. spectrum is made up of all the visible colors so to understand the spectrum of a light source we need to separate those colors represented in the spectrum and quantify them by amount and intensity to ascertain the spectral graph. the spectral graph of identical k-rated bulbs are usually not even closely related between different models and the peeks on the graph can be completely different widths and heights to make the exact same color so even bulbs with perfect k-ratings can put out light that's largely unusable depending on where and how intense the peaks are.

 

[gustavo85]

Hmmm I don't want it to be blueish...so 6,700K it is!

 

[dundadundun]

blue looks whiter green looks yellow. i suggest picking up both k-ratings and seeing for yourself. 10,000k is definitely a crisper color and more pleasing to the eye, IMHO.

 

[jpappy789]

As dun said there is no such wavelength (within the visible spectrum) that a plant CANNOT use...it's just that certain ones are more or less useful. The differing pigments pretty much cover the entire spectrum.

 

[SubRosa]

Plants don't use K ratings they use certain wavelengths of light, mostly two narrow bands one in the blue end one in the red end. Sunlight on the surface of a body of water has a K value of about 6500. As light passes through water it is filtered out but not evenly. The red end of the spectrum is filtered out much more rapidly by water than the blue end which is why deep water pics always look so blue and why deep water fish are often a bright red color. At the depths the live at red is black. This change in spectrum corresponds to higher K values as you go deeper.