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I bought a 96 watt compact flourescent for my 38 gallon. I was planning on setting up a planted tank. Is a 10,000K spectrum good for a planted tank?

(It is a 50/50 with actinic blue).

†Aquapickle†

Hi,
Actually, it is way too much IMO, for that tank.
10,000K is the beginning of the range for saltwater reef
tanks and the "top end" of what might be used on freshwater
tanks. At that high a "K" rating, the light is so bright
that it tends to wash out some of the greens in the plants.
Personally, I would stick with lights in the 6700-8800K
range. "Daylight" is considered to be at about the 6700k
range and is ideal for viewing fish and growing plants.

The actinic blue is way higher in the "K" rating and
actually gives of light with a bluish tinge, hence the
name actinic Blue. The 10,000K white light is used to
smooth out the blue color and make us humans see white
light. That bulb would best be used in a saltwater
application.

Frank

-->>> The Confidence of Amateurs, is the Envy of Professionals <<<--

Plain 10,000k bulbs can work fine. I use them most of the time and find the ratings under 8,000k to be yellow although most people prefer 6,500-6,700k for bringing out the greens in a planted tank. 50/50 bulbs will not work. A 50/50 and a 10,000k are quite different. The 50/50 is only half 10,000k and half solid blue or actinic light. That blue half will be wasted since plants can't use that much blue without other spectrum light(red especially) to counter it. Unless your really over lighting your tank you'll just grow more algae than plants since the plants can only use half the light your putting on the tank. Your better off getting a bulb that is only 10,000k or a lower rating.

So is there such a thing as a compact fluorescent light without actinic blue and with less than 10,000K?

†Aquapickle†

I found this as a possible replacement what do you think? Is it compatible with my coralife fixture? ( it is a square pin fixture).

This is a "Current" Brand bulb
http://www.drsfostersmith.com/Product/Prod_Display.cfm?pcatid=11422&N=2004+113346

I was looking at the 6,700K or 6,700K whatever that is.

†Aquapickle†

Hi,
As long as the pin arrangement on the base is the same
and the wattage is not more than the original bulb, then
it will work perfectly. I have a hood on my 30G tank with
two similar, 65 watt, bulbs. I use a timer on mine so
that one light, the one connected to the fan, comes on
and stays on for 10 hours a day. A second timer turns on
the second light from 10 to 2 every day, duplicating the
most intense lighting period of the day (when the sun
approaches, and passes through noon.).


The light from bulbs is rated in Degrees Kelvin.
It gets its name from the scientist who created the rating
system. It is based on a solid black metallic object.
As you heat the object it starts to turn colors ranging
from red to yellow to white to blue. Much like an electric
stove burner turns from black to red. Or a piece of metal
heated by a torch goes through the color shifts before it
melts.
Plants prefer light in the red and blue spectrum, but...
Neither of them allows us (humans) to see colors in those
lights. Look at a display with red lights and all you see
are grays and blacks, the same with blue light. You need
white light (about 2000K to 10,000K) to see colors.
Here is a site that might interest you:
http://www.1000bulbs.com/page.php?s=KelvinTempExplained

Frank


-->>> The Confidence of Amateurs, is the Envy of Professionals <<<--

Thanks for the help Frank. I read somewhere that the best Plant spectrum was around 6,700K. This 50/50 bulb came with the fixture and i was questioning whether or not it is a good plant bulb. Thanks again!

†Aquapickle†

Hi,
The idea of lights in an aquarium are to allow
us to see our fish, in their true colors, and, to
allow us to grow plants in their tanks as well.

As you can see in the chart above light at the low end
of the spectrum has a yellowish glow, growing whiter and
brighter as you go up in "K" rating. At the top end it
starts to turn more and more blue. To see the fish and
plants without the light unduly affecting their colors
you would want light in the 6000 to 8800K range. This
range is best for viewing the fish, and growing the plants.

In certain circumstances, you might shift to a higher "K"
rating say to 10,000 if you had what is called a "show"
tank, where the height of the tank is around 24 inches.
At that depth, the water column scatters the light energy
and absorbs it, so while you might have 3 wpg at the
surface, by the time the light gets to the surface of the
gravel it is something less. The 10,000K bulb is at the
bluer end of the spectrum and blue light penetrates the
depths further than the red (lower) end does.

Note also in the chart the use of the words "Warm" and
"Soft." These lights are designed for reading and do not
give off the harsher, brighter, white light that the bulbs
labeled DAYLIGHT or SUNLIGHT do. The latter ones are
designed to resemble the sunlight and are also the best for
plants.

Frank

-->>> The Confidence of Amateurs, is the Envy of Professionals <<<--