Hi. I have a question. They sell these fluorescent bulbs here in the US to
replace regular incandescent bulbs. They use the same hardware, so you can
use them in your regular lamps, etc. They say these bulbs' lower wattage
is equivalent to higher wattage incandescents:
http://www.energystar.gov/products/cfls/
So, if I were to use these for adding light to my aquarium, which wattage
do I count? The 20 watts the bulb actually uses or the 60 watts it is
equivalent to?
Hope this is not a dumb question...

Cheers.

Victor M. Martinez | The University of Texas at Austin
| Department of Chemical Engineering
http://www.che.utexas.edu/~martiv | Austin, TX 78712
If we knew what we were doing it would not be called research, would it?

So, if I were to use these for adding light to my aquarium, which wattage
do I count? The 20 watts the bulb actually uses or the 60 watts it is
equivalent to?

Use the watts the bulb actually uses.

When planted tank folk talk wattages, they are almost always talking
flourescent wattages.

Incandescent light is much less efficient than flourescent, so no one uses
incandescent light, or incandescent light equivalents, for planted tanks.


Leigh

http://www.fortunecity.com/lavender/halloween/881/

LeighMo wrote:
Use the watts the bulb actually uses.

Thanks!

When planted tank folk talk wattages, they are almost always talking
flourescent wattages.

I kinda figure that, but got confused with the metal halide stuff.

Incandescent light is much less efficient than flourescent, so no one uses
incandescent light, or incandescent light equivalents, for planted tanks.

Ok. Now... those bulbs say they last for 5 years or so. Do I still need to
change them after 6 months?

--
Victor M. Martinez | The University of Texas at Austin
| Department of Chemical Engineering
http://www.che.utexas.edu/~martiv | Austin, TX 78712
If we knew what we were doing it would not be called research, would it?

Ok. Now... those bulbs say they last for 5 years or so. Do I still need to
change them after 6 months?

I think most people do. The reasoning being that even when the light still
looks bright to human eyes, the intensity falls off enough over time that it
should be replaced.

I have no idea if this applies to this kind of bulb, though. Maybe Wayne knows


Leigh

http://www.fortunecity.com/lavender/halloween/881/

Ok. Now... those bulbs say they last for 5 years or so. Do I still need to
change them after 6 months?

Light is sorta a "religious" issue with both plant and reef guys, ask around
and you'll prolly hear just about everything concerning light levels,
burn-in, proper color temperature, etc etc etc....

So here's how I cope with it... if my foreground is growing well I have
enough light. Other than that I (and many others) have ignored a lot of the
web lore and continued to use bulbs way past their rated lifetime. Until I
see my high light plant's growth seriously comprised I don't do a thing. A
lot of net wisdom on lighting is from the reef guys, which is fine, but some
corals are orders of magnitude more sensitive to lighting levels (and color
temperature shifts) than freshwater plants... hence the suggestion to change
out every six months. A 20% change in light levels may cause a coral to
expel its zoozanthallae but it's not going to cause plant death. I think
changing every six months without evaluating your growth rates is throwing
money (and a perfectly good bulb) away.

Cheers,
Jeff Ludwig

On Sun, 20 Oct 2002 17:56:57 -0500, "Victor M. Martinez"
wrote:

So, if I were to use these for adding light to my aquarium, which wattage
do I count? The 20 watts the bulb actually uses or the 60 watts it is
equivalent to?

You use the lower wattage, which is the actual wattage used by the
fluorescent light. If you are trying to achieve a certain "watts per
gallon", you need to be aware that those rules only apply to
fluorescent lights. That's why you use the actual wattage of teh
flourescent light.

The "equivilent to" wattage really just points out how much energy an
incandescent light wastes as heat.


Chuck Gadd
http://www.csd.net/~cgadd/aqua

"Victor M. Martinez" wrote in message
...

Ok. Now... those bulbs say they last for 5 years or so. Do I still need to
change them after 6 months?

Yes. They are the same as any other compact fluorescent tube,
except that the ballast is built into the socket. So, their light
output deteriorates at the same rate as any other fluorescent.

However, it seems that the 6 months replacement time commonly
quoted for fluorescent tubes is too conservative, at least for some
tubes. 6 months corresponds to around 2,200 operating hours (at
a little over 12 hours per day). Looking at the graphs published
by Osram for the Lumilux T8 tubes, we find that, after 12,000 hours,
we still get 90% of the original luminous flux. In fact, even after
over 20,000 hours, the graph still shows nearly 90%.

I don't know how these figures compare with fluoros from other
manufacturers. But it might pay for you to check out what
your tubes are claimed to do -- you may be able to stretch out
the maintenance interval quite a bit.

Cheers,

Michi.

--
Michi Henning Ph: +61 4 1118-2700
Triodia Technologies http://www.triodia.com/staff/michi