This article is part of a three part series on aquarium lights; be sure to read the entire series! In part 1 of this series on aquarium lights, we talked about how the fish and animals you are keeping will influence the type of light you need for optimal health of your aquarium.
We also talked about how lights are available in different color wavelengths.
Now let's give some consideration to the types of bulbs that are available as lights.
Incandescent Lights Incandescent bulbs generally are not the best choice for lights because the light they produce tends to promote unwanted algae growth.
Incandescent bulbs are generally cheap to buy, but are not very efficient to operate, using only about 10% of their energy to produce light, while the rest produces heat.
The heat they produce can be useful in some instances, for reptiles for example, but there are better ways to heat your aquarium.
In terms of color, normal incandescents fall in the 2700K range and 3000K for halogen lights; both of these are on the red/yellow end of the spectrum.
Fluorescent Lights The most common choice for lighting is fluorescents.
Fluorescent lights do not produce unwanted heat, and they can provide light over a larger area.
They are generally inexpensive and readily available.
However, the light they produce is not as intense as with incandescents, and the bulbs take up more room.
Their light production typically dims over time, so you will need to replace them on a regular schedule even if they are still burning.
Do not buy a household fluorescent bulb not intended as an aquarium light for aquarium use; it will not provide light in the correct color wavelengths for optimal aquarium health.
Fluorescent bulbs can produce light in a variety of color ranges.
NO, HO, and VHO Fluorescents A normal fluorescent bulb is rated is NO, for Normal Output.
These bulbs may also simply be labeled "color enhancing," or "good for plant growth.
" These NO bulbs work with standard fixtures.
To compensate for the fact that fluorescent bulbs in general produce less intense light than incandescents, manufacturers now produce High Output, or HO, bulbs, and Very High Output, or VHO, bulbs.
HO and VHO bulbs are especially useful for deep tanks, reef tanks, and tanks with lots of plants.
HO and VHO bulbs are higher wattage bulbs as well.
HO and VHO bulbs require special ballasts; these usually come with the light fixture itself.
VHO bulbs and fixtures can be hard to find.
If you need or want that kind of intensity, consider our next category of lights, compact fluorescents.
Compact Fluorescents Compact fluorescent bulbs, or power compacts as they are sometimes called, are one of the newest trends in aquarium lights.
These bulbs are sized the same as NO fluorescents, and produce more light intensity using less power.
Consequently, they are less expensive in the long run even though their initial price may be slightly higher.
Many owners of reef tanks are switching to compact fluorescents rather than using the hard to find VHO bulbs and fixtures.
These bulbs are available in almost all color wavelengths as other lights.
Compact fluorescents require special fixtures.
Choose from a new fixture or a special kit to retro-fit your existing fixture.
Additionally, compact fluorescents are considered either straight pin, or square pin, depending on whether the four pins at their ends are arranged in a straight line or a square.
These are not interchangeable, so make sure to buy the right kind for your fixture.
Metal Halide Bulbs Metal halide bubs are generally not recommended for beginners.
These are classified as HID, or high intensity discharge, lights.
If you've ever been to a football stadium or baseball game, you've seen HID lights.
These lights produce a very high intensity light for their size.
But what's good on the playing field can be problematic in the aquarium.
Metal halide bulbs produce exceptionally intense light that gives the kind of shimmering effect often seen in shallow reefs.
This is a beautiful effect, which makes them a favorite for the more experienced saltwater aquarium keeper who favors corals, anemones and other animals that crave light.
However, that intense light can cause a multitude of problems.
First, metal halide lights can create hot spots, because their light is focused on a small area.
This can cause problems with aquarium overheating; fixtures for these bulbs often include cooling fans.
Unshielded metal halide lamps can even give you sunburn.
Second, the surface of these bulbs gets extremely hot.
Never touch a metal halide bulb that is turned on, or that has been turned off for less than one full hour.
Never touch the bulb with your fingers at any time, as the natural oils from your hands will weaken the glass.
Avoid looking directly at the bulb when lit.
According to reports, some aquarium owners have experienced blurred vision when using these lights even without looking directly at them.
Most of these bulbs have glass or plastic filters to remove unwanted UV light.
Despite the need for careful use, metal halide bulbs can produce a wonderful effect in the aquarium, especially when combined with other lights such as lunar lights.
As far as colors, they are available in most colors as other aquarium lights, often in the 10,000K to 20,000K range.
We also talked about how lights are available in different color wavelengths.
Now let's give some consideration to the types of bulbs that are available as lights.
Incandescent Lights Incandescent bulbs generally are not the best choice for lights because the light they produce tends to promote unwanted algae growth.
Incandescent bulbs are generally cheap to buy, but are not very efficient to operate, using only about 10% of their energy to produce light, while the rest produces heat.
The heat they produce can be useful in some instances, for reptiles for example, but there are better ways to heat your aquarium.
In terms of color, normal incandescents fall in the 2700K range and 3000K for halogen lights; both of these are on the red/yellow end of the spectrum.
Fluorescent Lights The most common choice for lighting is fluorescents.
Fluorescent lights do not produce unwanted heat, and they can provide light over a larger area.
They are generally inexpensive and readily available.
However, the light they produce is not as intense as with incandescents, and the bulbs take up more room.
Their light production typically dims over time, so you will need to replace them on a regular schedule even if they are still burning.
Do not buy a household fluorescent bulb not intended as an aquarium light for aquarium use; it will not provide light in the correct color wavelengths for optimal aquarium health.
Fluorescent bulbs can produce light in a variety of color ranges.
NO, HO, and VHO Fluorescents A normal fluorescent bulb is rated is NO, for Normal Output.
These bulbs may also simply be labeled "color enhancing," or "good for plant growth.
" These NO bulbs work with standard fixtures.
To compensate for the fact that fluorescent bulbs in general produce less intense light than incandescents, manufacturers now produce High Output, or HO, bulbs, and Very High Output, or VHO, bulbs.
HO and VHO bulbs are especially useful for deep tanks, reef tanks, and tanks with lots of plants.
HO and VHO bulbs are higher wattage bulbs as well.
HO and VHO bulbs require special ballasts; these usually come with the light fixture itself.
VHO bulbs and fixtures can be hard to find.
If you need or want that kind of intensity, consider our next category of lights, compact fluorescents.
Compact Fluorescents Compact fluorescent bulbs, or power compacts as they are sometimes called, are one of the newest trends in aquarium lights.
These bulbs are sized the same as NO fluorescents, and produce more light intensity using less power.
Consequently, they are less expensive in the long run even though their initial price may be slightly higher.
Many owners of reef tanks are switching to compact fluorescents rather than using the hard to find VHO bulbs and fixtures.
These bulbs are available in almost all color wavelengths as other lights.
Compact fluorescents require special fixtures.
Choose from a new fixture or a special kit to retro-fit your existing fixture.
Additionally, compact fluorescents are considered either straight pin, or square pin, depending on whether the four pins at their ends are arranged in a straight line or a square.
These are not interchangeable, so make sure to buy the right kind for your fixture.
Metal Halide Bulbs Metal halide bubs are generally not recommended for beginners.
These are classified as HID, or high intensity discharge, lights.
If you've ever been to a football stadium or baseball game, you've seen HID lights.
These lights produce a very high intensity light for their size.
But what's good on the playing field can be problematic in the aquarium.
Metal halide bulbs produce exceptionally intense light that gives the kind of shimmering effect often seen in shallow reefs.
This is a beautiful effect, which makes them a favorite for the more experienced saltwater aquarium keeper who favors corals, anemones and other animals that crave light.
However, that intense light can cause a multitude of problems.
First, metal halide lights can create hot spots, because their light is focused on a small area.
This can cause problems with aquarium overheating; fixtures for these bulbs often include cooling fans.
Unshielded metal halide lamps can even give you sunburn.
Second, the surface of these bulbs gets extremely hot.
Never touch a metal halide bulb that is turned on, or that has been turned off for less than one full hour.
Never touch the bulb with your fingers at any time, as the natural oils from your hands will weaken the glass.
Avoid looking directly at the bulb when lit.
According to reports, some aquarium owners have experienced blurred vision when using these lights even without looking directly at them.
Most of these bulbs have glass or plastic filters to remove unwanted UV light.
Despite the need for careful use, metal halide bulbs can produce a wonderful effect in the aquarium, especially when combined with other lights such as lunar lights.
As far as colors, they are available in most colors as other aquarium lights, often in the 10,000K to 20,000K range.