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Aquarium Lighting
Probably no other topic in reef keeping is as controversial
or more hotly debated than aquarium lighting. Many articles
are written about it and there is much confusion about it
in the industry..
You could write an entire book on lighting alone. But we
are going to tell you what works for us. It may not be the
best solution and, but it's really works for us, and hopefully
it will give you a starting point. And then later on, you
can make any adjustments that you think are important.
The aquarium industry has developed special light bulbs that
have led to the success of keeping corals in captivity. It
is important to use these bulbs.
When you're looking at the type of lighting that you want
to use you should first consider what type of corals are going
to keep. the soft corals don't require as much light and SPS
corals require the most light. So if you're a beginner and
starting off on soft corals and you can actually choose a
wide variety of lighting, starting with some of the lower
lights.
We've been surprised by how very low light levels can be
used to keep our hardy beginner corals alive. We've even had
corals such as mushrooms surviving and growing under 40 W
fluorescent balls, although we don't recommend them. They
do well in the compact fluorescent holds and metal halides.
You have to be careful with soft corals that you don't give
them TOO much light because they can reach a saturation point.
This is the point where the coral gets too much light and
starts to shut down because of oxygen poisoning.
There are two main things you want to consider when talking
about lighting: intensity and the spectrum (wavelength or
color temperature) of the bulb.
Intensity
Intensity refers to how strong the bulb is. How much light
it puts out.
A standard 40 Watt bulb is not going to give you any where
near enough intensity to keep corals healthy. The minimum
coral wattage for metal halides is 175 Watts . A typical 75
gallon tank would use at least 2 -175 watt bulbs at a minimum
if keeping soft corals, and 2-400 watt bulbs if keeping SPS
corals. A few really large tanks might us 1000 watt bulbs,
but that may be overkill and running electricity for 100 watt
metal halides is very very expensive.
Spectrum
Color temperature, or spectrum, is the wavelength that the
bulb produces. Why is this important? Because photosynthesis
in nature occurs primarily in the blue spectrum range, (which
is the 427 nm range) so ideally you want to provide as much
light in the blue range as possible. So why don't you just
provide only blue light to your tank? Well, because the corals
don't look natural that way, When you view them and they will
glow like a poster under blacklight, which is not natural.
And the aquarium is much darker to the eye. So we actually
recommend a combination of blue light and white light.
The reason you can't use just a standard light bulb even
if it has the correct wattage, is the spectrum. A metal halide
bulb from Home Depot gives off a very yellow color, not blue,
so it's not the correct spectrum and also doesn't have enough
the right color temperature that helps corals photosynthesize.
Fluorescent Bulbs
If you're using fluorescent tubes , we like the ratio of
bulbs to be 1 to 1. This means 1 white daylight bulb for each
blue Actinic type bulb. This way you will be sure that you're
getting the benefit of the blue wavelength, while also getting
white light wavelengths so that you can view it normally.
Tubes such as the VHOs (very high output) light are commonly
found in the industry and highly recommended. You can also
mix different types of bulbs such as fluorescent bulbs and
metal halides bulbs as long as you use the correct ballast.
LED (light emitting diodes) are becoming more popular for
lighting aquarium since they use so little electricity. Although
the cost of the LED initially is very high, their usage of
electricity is very low and we are hoping in the future that
these become more common and the price comes down. That will
allow us to reduce costs to grow out your corals.
Metal Halide Bulbs
The advantage of metal halides and is that they are widely
available in many different intensities and color temperatures
and they have the most available intensity of any light bulbs.
Not only do you need the right color temperature but also
some corals need a higher intensity such as the stony corals.
We actually use a combination of metal halides and fluorescent
bulbs on most of our tanks, but you can easily go with metal
halides only if you wish.
We recommend either a 10,000K of 14,000 K bulb to start out.
10K refers to 10,000 Kelvins, which is a measure of color
temperature, but all you need to know is, this is a bluer
bulb than a 5500 Kelvin bulb. As you go higher up in the color
temperature number, the bulbs become bluer, but they also
become more expensive too.
You can buy a 5500 K bulb at a home improvement store about
20 bucks but the color spectrum, being so yellow, is not going
to be advantageous for the corals. It cant be of use, because
the PAR value of that light is not very high. 10,000 K seems
to be the standard for the industry for the hobby currently
and is readily available and fairly economical. You can also
choose a bluer 14K bulb, or even 20 K which are very blue.
Many people use 20Ks on SPS systems. On our systems we tend
to use a combination of all three of these MH bulbs. In addition
to using these, we also supplement them with actinic VHO bulbs
which means a solid blue bulb in a very high output. We do
this because we are looking for the maximum intensity and
the maximum amount of grow out possible for corals.
Ballasts
You can use many different spectrums of light bulbs (5.5K,
10 K, 14K, 20K) as long as the Wattage (175 watt, 250 watt,
400 watt, 1000 watt) matches your ballast. So you arent locked
into the color temperature when you buy a ballast. But you
are locked into the Wattage (which determines the intensity)
Lighting is a topic that can be debated forever, but we try
to give you some basics that will get you started in the right
direction. Even if everything else is right in your system
if you don't provide the correct lighting your corals will
not do well. The source of all life on earth is the sun. And
with your corals, the source of their life starts with the
lighting you give them.
By giving them the proper lighting you'll be well on your
way to provide an environment to allow them to grow up to
be healthy and happy corals.
Lighting - VHO Ballasts
Lighting - Ballasts- General Info
Lighting-
Metal Halide Ballasts ( 10k, 14k, 20
Lighting-
Flourescent Ballasts
Lighting-
Power Compact Ballasts
Lighting
- Actinic bulbs
Lighting
- Fluorescent bulbs
Lighting
- Metal Halide bulbs
Lighting-
VHO (Very High Output) bulbs
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