Choosing Aquarium Lights - Part 1 - Your Fish and the Color of the Light

This article is part of a three part series onHere's a quick rundown of the various lighting
aquarium lights; be sure to read the entire series!options.o Lights rated at 5500K and below are
Choosing the proper aquarium lights is verytypically incandescent bulbs in the red/yellow
different from lighting your home. At home, youwavelength. These are not good choices for
probably just buy a bulb that fits the fixture, putaquarium lights as they promote excessive algae
it in place, and go on your way. Your biggestgrowth. Natural sunlight is also to be avoided for
choices are between overhead lighting and lamps,this reason.o 6500K lights are lights in the greenish
and traditional incandescent bulbs and compactyellow wavelength. They are appropriate for
fluorescents.freshwater tanks that are somewhat shallow
If you own an aquarium, however, lighting(these lights are not good at penetrating deep
becomes a more important consideration. Afterwater), as a supplement to saltwater or reef
all, if you keep pets in an aquarium, you aretanks using actinic light (more on that below), and
responsible for providing them with a healthyfor live plants.o 10,000K lights produce a white
environment that closely mimics their naturallight with a light bluish cast. This is a good choice
habitat. To do this successfully, you need a fewfor most tanks, including freshwater and saltwater
pieces of information.tanks, and especially reefs tanks and tanks for
What's in your aquarium?deep water fish and plants. This type of light
The first step in choosing lights is knowing whatreally shows off the beauty of your animals and
type of animals and plants you will be keeping inplants to best advantage.o 12,000K to 20,000K
your tank. For the purposes of this article, we willlights produce very intense white light with an
be focusing on the care and keeping of fish.oincreasingly bluish cast. These lights are best when
Freshwater fish: These are fish common tothe tank is deep, or you have fish that are
freshwater lakes and rivers, and are oftennatives of very deep water.o Actinic light is not
referred to as "tropical fish." Freshwater fishrated on the Kelvin scale. The numbers you will
include goldfish, guppies, swordtails, and cichlids.see on actinic bulbs are 420nm or 460nm, which
Freshwater tanks may also include plants whichare nanometer measurements. Think of actinic
grow in freshwater.o Saltwater fish: These arelight as being on the very upper end of the blue
fish and animals found in the ocean. They requirespectrum nearing the ultraviolet range which we
the owner to prepare a saltwater solution thatcannot completely see. The use of actinic light as
replicates ocean water as closely as possible.aquarium lights is still undecided. They are most
Popular saltwater fish include damsel fish, clownappropriate for reef tanks, and are often used in
fish, triggerfish, pufferfish, sharks, and more.combination with other lights to provide light that
Other common "pets" in saltwater tanks includemore closely represents the full spectrum of
sea stars, anemones, sea cucumbers, and fannatural light.o Lunar or moon lights typically
worms.o Brackish water: Fish who live whereproduce a blue light that does not provide much
freshwater and saltwater sources meet are saidillumination, although white lunar lights reproduce
to live in brackish water. The water in a brackishthe light of a full moon. These lights are usually
tank is less salty than that used for saltwater fish.LEDs and can be used in any type of tank, but
Mollys are among the most popular brackishare most useful when you need to simulate lunar
water fish. Generally, lighting requirements for acycles to breed fish.
brackish water aquarium are the same as for aDifferent colors of lights function better for
freshwater aquarium.o Reef tanks: These aredifferent purposes. For example, a light that is in
saltwater tanks that include more than just fish,the greenish to yellow spectrum is good for the
such as living coral, living rock, living sand, etc.growth of live plants. Saltwater aquariums often
What color is your light?do well with light from the blue end of the
We generally think of light as having no color. Butspectrum. Toward the red end of the spectrum,
think about what happens when light shinesa light begins to produce more heat than light;
through a prism. The rainbow that results isthink about the infrared lights you see over the
because ordinary light has been broken up into itsfries in a fast food restaurant.
various color wavelengths. Without a prism, theseWhen choosing aquarium lights then, knowing
different color wavelengths are quite difficult forwhat kinds of fish, animals and plants you will be
the eye to distinguish, but they are there. Thekeeping will help you know what color of light to
color of light is expressed according to the Kelvinbuy.
scale, which also measures light temperature.