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Re: CF light temps

>I presume you are talking about the /950 (5500 K, CRI > 90) and /860 (6700 
>CRI > 80) 55 watt bulb types. I have both side by side. The 6700 is a great
>color, looks white to me, compared with the slightly yellow of the 5500.
>The difference in CRI is hardly noticeable unless you do specific 
>The colors (both plant and fish) are a little more saturated with the CRI > 
>bulb, a little washed out with the CRI > 80. But I can see this only 
>they are side by side, and I can swap the bulbs in the fixture. With only
>one bulb type, it would be impossible to detect any effect. The 6700 is 
>way brighter, 4800 initial lumens as opposed to 3800 from the 5500. In PAR
>terms they are similar though. The plants do well under any one of them. If
>you like a brighter, whiter look, go for the 6700.
>You can find the 6700 with 2G11 base at AH Supply. There are other types of
>color in the 55 Watt size nowadays though. Take a look at
>(select Lighting in the product index, go to the " Compact Bulbs & DIY 
>parts "
>section, and look for the Realux types). I would like to experiment with a
>pink/white mix.
>I think 10,000 K by itself wouldn't do any good for the plants, those bulbs
>have almost no red component, and plants need red light too. Maybe mixing
>10,000 with some lower temp bulb would be OK. The possibilities seem
>- - Ivo Busko
>   Baltimore, MD

I agree with what you have to say, but I find the Kelvin rating very 
misleading. A 9235 K All Glass Aquarium lamp looks as though it has a strong 
red and blue component. Even with the strong red component it is still 
listed at 9325 K, not far from 10,000 K. This is why I asked for opinions 
from people, like yourself, who have actually seen the lamp under planted 
tank conditions. My guess is the All Glass 9235 K lamp has a very low CRI, 
but when I saw it at the LFS it appeared fairly balanced (a little pink). 
Unfortunately, all manufacturers do not provide spectral density plots for 
their lamps, if accurate they would be helpful in selecting lights.

Is there a better way of determining the appearance of a lamp than to go by 
the K temp and CRI?

For now, I am in agreement with you and will most likely purchase the 6700 K 
lamps at AHSupply, although the Pink/White Realux does sound interesting.

Thanks for all your help.


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