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Re: CF light temps

"allan Mlodick" <allangm at hotmail_com> wrote:

> Hi All,
> Its getting to be the end of the usable life for my two 55W CF lamps and I 
> will need to buy new lamps. Before I spend my cash, I was wondering if some 
> of you could give me some help on the color/appearance, of a planted tank, 
> under the different lamp temps?
> I presently have 5500K lamps, but find them just a bit to yellow-green in 
> color balance. Has anyone tried the 6500-6700K range in a CF? and how would 
> you describe the color balance? There is also a 10,000K lamp available, 
> would this be to blue, and suitable only for Marine environments?
> The lamps I use are Euro type (4 pins in a straight line) so please don't 
> reccomend any of the Japanese type, it won't help me much unless they are 
> available with both socket types.
> TIA,
> Al

I presume you are talking about the /950 (5500 K, CRI > 90) and /860 (6700 K,
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 experiments.
The colors (both plant and fish) are a little more saturated with the CRI > 90 
bulb, a little washed out with the CRI > 80. But I can see this only because 
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 also 
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