AC/DCdude17 wrote in
:

X-No-Archive: Yes

David Wee wrote:

I was browsing thekrib
(specifically
http://www.thekrib.com/Plants/Tech/light-spectrum.html concerning the
post Color spectrum Vs Degree Kelvin??)

since I was planning on getting a 6x13W compact flourescent( yes,
thats 1x13W individual ballasts) for my 10 gallon, to upgrade.

The offering of bulbs are as follows

2700K
3500K
4100K
5000K


The combination sounds like the typical trichromatic fluorescent
lamps. They are optimized specifically to human eye's sensitivity
curve and they achieve higher efficacy by concentrating output in what
our light receptors are sensitive to. They have higher efficacy at
illuminating, because our eyes are more sensitive to their output, but
they're probably not suitable for plant growth.


I use a 3500K CF bulb, I get excellent plant growth, without CO2, it's
about 1.5Watts/gal.

Take a look at this site to see what difference the bulb temperatures can
have:
http://www.culbertfamily.com/jenya/aquarium/lights/
it's really nice to see the combination of bulbs and thier effect.


Now I could get an assortment, i.e. 2 of each color temperature,
but i read that plants photosynthesize best at under high red
spectrum lighting. So im concerned about selecting the best color
temperature bulb since I (think) i want to go with strong reds in my
light selection.

The red from typical trichromatic lamp is what red receptor is most
sensitive to. I don't know the exact wavelength, but if it doesn't
coincide with the red plants likes, it probably won't work good.

Color temperature of 5,000K CCT means the black body radiator
temperature the lamp looks closest to. The spectrum of Colortone 50
and 5000K trichromatic lamps are very different even though they look
similar in color.