[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: compact fluorescent 16.5" biax

>I have a (2) bulb 16.5" biax light fixture that I have taken apart and built
>into a custom hood. I'm looking at buying the lamps and don't know what
>Kelvin rating I should look for. Can you guys help? My local electrical guy
>has 3500K and 4100K. I was told I should get one Actinic. What K-rating do
>the Actinic bulbs have? Am I ok with either of these two lamps that are
>stock or would you recommend I special order? I have a 29-gallon freshwater
>tank with yeast co2 generator and freshwater plants. CRI, Lumens, Kelvin
>ratings, blah blah blah. Beats me! help!

Whoever told you needed an actinic bulb in there was probably a reefer. The
reefs need a *lot* of blue in their light to simulate their depth in marine
locations and to keep the coral happy. I've never heard of anyone saying it
was of any benefit to a planted tank (I've heard comments to the contrary
though). Actinic bulbs are pretty much all in the blue, so their kelvin
rating will be very high. I'm not sure of an exact number, but I would
guess 20,000K+

As for those two bulbs you mention, I think you'll find that either 3500K
or 4100K is going to be too low K (too yellow) for you. 3500K is close to
incandescent color-wise, with a typical incandescent bulb being about 2900K
ro so and about 3200K-3600K for halogen lamps. Most find this range too
yellow for their tastes, although people have had success growing plants
under these. The 4100K is probably a cool white. I'd look for something in
the 5000K-6700K range, with the higher color temperatures having a bluer
and thus "crisp white" appearence. Stay away from the 10000K and higher
lights which are primarily intended for reefs and will be *very* blue.

You could probably balence out the 3500K with an actinic, but it will
result in a weird spiky spectrum. I'd look for two 5600K or so bulbs


Waveform Technology
UNIX Systems Administrator