Saltwater Aquarium Lighting Guide

Most people prefer to buy a plastic hood for their tanksufficient. For reef aquariums, you need to ensure that
that includes a cover and lighting. Most packagesyou select enough watts for the number of gallons of
contain either one or two fluorescent bulbs that arewater your tank holds. A 55 gallon aquarium, for
built in to the hood. This type of setup is very simple.example, would need at least 165 watts, and up to 275
You just place the hood on top of the tank, plug it in,watts in order for photosynthesis to effectively take
and turn it on.place.
Standard normal-output fluorescent bulbs are perfectlyIn order to get that kind of wattage, you might need as
acceptable for fish-only tanks, but they will not be ablemany as 4-6 fluorescent tubes, which is far more than
to support photosynthetic animals, and they will not beany standard hood can accommodate. Thus for
bright enough to accommodate other marine animalsmarine aquariums, one must generally choose VHO
than need extreme amounts of light to survive.bulbs which require special ballasts. Or you could
Saltwater Reef Aquarium Lightingchoose to go with metal halides instead.
If you intend to create a reef aquarium, your lightingPlease note that a pre-made lighting system is NOT
needs will be different. For example, even placing asuitable for reef tanks. You will have to develop your
piece or two of live rock or soft corals will require youown custom setup if you want the best possible
to replace at least one of the bulbs in your hood with asolution. Some people use egg crates in their halide
higher Kelvin normal-output bulb. A 10,000K bulb willsystems, but this is not advisable. A 250 watt halide
usually be sufficient for some reed life, but only softbulb will melt egg crates!
corals like mushroom coral (actinodicus) and sea matsSaltwater Aquarium Lighting - Metal Halide Bulbs
would be able to live under the low lighting provided byThe trouble with metal halide bulbs is heat. They get
two of these tubes.very, very hot. You've probably touched a normal
Saltwater Aquarium Lighting - Types of Bulbs70-100 watt light bulb in your house before. They get
There are four main types of fluorescent bulbs:quite warm, but a 250 watt incandescent metal halide
1. NO - Normal Outputbulb will cause your tank temperature to rise
2. HO - High Outputprecipitously.
3. VHO - Very High OutputSaltwater Aquarium Lighting Tips
4. PC - Power Compacts (also known as Osram)You will need to make sure your hood keeps the bulbs
There is also another type of bulb altogether knownat least 12 inches away from the water surface, ideally
as metal halide (MH). Metal halide bulbs are rated solelyeven higher. A distance of 15 inches would be better.
by wattage and spectral output. Since iodines andThis will allow some air to move between the bulbs
sodiums are not suitable for marine aquariums, youand the water, but you will still need to use fans or a
absolutely must avoid the type of metal halide bulbscommercial chiller. Chillers can cost $500 or more, so
that are found in commercial buildings and parking lots.this may not be a good option for you. But fans are
Saltwater Aquarium Lighting for Fish-Only Systemsacceptable for cooling if you cannot afford the added
For fish-only systems, standard fluorescent bulbs areexpense of a chiller.