Color Temperature

[Phal grower]

Hello everyone!

I was just wondering what color temp you use for your flourescents, or if you use a combination of color temps? Thankyou all.

[fishmommy]

I really prefer 10,000K for the way it looks - much whiter than 6,700K or 9,600K.
Plants seem to like it, but I can't say it's better than lower K lights.

[RJSquirrel]

I like 5000k bec I have to live in the same lighting and
Im already at solar flare status.I wear flash goggles at 6 am when they fire up. No they dont turn on thats right they Fire up

[glengary54]

Too, too funny!!!!

[Paul Mc]

Home Depot sells some that are within the 5600 range and they are really good. If I'm remembering correctly, you want to shoot for somewhere between 5500 and 7000. The member Ray is much better at this information than I am, but I think that was close to what he recommended.

You should check out Ray's profile and website, perhaps email him directly. Or hopefully, he will respond. He's the best at this kind of information.

[Merlyn]

IF we're talking about 4' T8 bulbs, I just bought a ten pack of the brightest Home Depot had at 6500K for approx $25.

Fishmommy, What kind of bulbs do you get 10,000K from ? I bet it's CFL 100 watt bulbs or HID fixtures.

IMHO, the CFLs have their purpose but they don't cover the area a 4' bulb does and to accomplish covering the same area would be much more expensive at 100 watts each vs 32 watt T8s ! That's IF you're worried about financial efficiency !

Mr. Ray is the one who knows all the facts.

[Ray]

10,000°K bulbs are intended for use on fish/coral tanks, so the spectrum gets the correct shift upon entering the water, yet still gives them the "actinic" (UV) part of the spectrum they need that plants don't..

6400-6500°K most closely matches the absorption spectrum of chlorophyll, and is described as "full noontime sun plus the blue back-scatter from a cloudless sky".

If you have Java on your computer, I have a neat little script that shows the spectrum by color temp, with an approximation of the appearance: Light Sources & Color Temperature

[fishmommy]

it's true, my terrariums are converted aquariums so I use aquarium fixtures. CFL.

[Phal grower]

Thanks for the feedback. Funny and educational Will 6500k lights provide enough red light for blooming? I use a 6500k and 3000k combo. I looked a Rays "color temp" site and it looks like the same amount of red.

[Ray]

Originally Posted by Phal grower

Thanks for the feedback. Funny and educational Will 6500k lights provide enough red light for blooming? I use a 6500k and 3000k combo. I looked a Rays "color temp" site and it looks like the same amount of red.

You didn't look at the scale, did you?

Forgetting the complex units, the 3000°K bulb puts out a level of 2 units in the red end of the chlorophyll absorption spectrum, and roughly 0 in the blue.

By contrast, a 6500°K bulb puts out about 100 and 125 units, respectively.

In effect, that means that to get the same red output as a single 6500° bulb, you'd need 50 3000°K bulbs of the same wattage! And you still wouldn't have enough blue.