Fluorescent Aquarium Lighting Basics

Fluorescent light bulbs

Fluorescent light bulbs or tubes are the most common form of lighting used on aquariums. Fluorescent bulbs are available in many sizes, and types, which make them suitable for almost any aquarium application. Fluorescent light bulbs are what are known as gas discharge light bulbs, they produce light by applying an electrical current to mercury vapors within a tube. The tube contains phosphor materials which fluoresce, when exposed to ultraviolet light that is produced from the excited mercury vapor. By using different phosphors, different spectrums of light can be produced, resulting in many different custom spectrums of fluorescent light bulbs being available for aquarium use. Fluorescent lights are energy efficient, fluorescent lighting systems are more expensive than incandescent lights, because they require a ballast to convert a standard electrical source, into the specific electrical supply needed for the bulbs to operate. There are several types of Fluorescent bulbs available to the aquarium hobby, each with a specific purpose, and useable lifespan. Because Fluorescent bulbs contain mercury, they should be recycled properly, in accordance to local regulations.

These are the most common types of Fluorescent light bulbs:

Standard Fluorescent:

These energy-efficient, cool ­operating, bright bulbs are ­available in a variety of lengths, wattages and spectral outputs. Standard fluorescent (also referred to as NO, or Normal Output) bulbs are ideal for general aquarium use. Standard fluorescent bulbs are available in T5 and T8 styles, with T8 bulbs being the most common standard fluorescent available. T5 and T8 bulbs are not interchangeable; each has its own pin spacing. Standard Fluorescent bulbs should be replaced every 12-18 months for maximum performance.

Compact Fluorescent (CFL):

These bulbs are high output, high efficiency, and moderate heat bulbs for aquarium use. Compact Fluorescent bulbs use a multiple tube design, and all the power connections are on one end of the bulb. The power connection, or pins, can be two different styles. The pin connection can either be a straight pin design (European style) or a square pin design (Japanese style); each type is designed for a specific fixture. Compact Fluorescent bulbs are available in most popular Kelvin ratings and wavelengths. Compact Fluorescent bulbs should be replaced every 8-12 months, for maximum performance. Compact Fluorescent bulbs are recommended for planted and reef aquariums up to 24 inches deep or any application where more lighting power is needed vs. standard fluorescent bulbs.

High Output (HO) T5 fluorescent:

These bulbs look the same as Standard T5 Fluorescent bulbs, but as their name suggests, they have greater power consumption and output, and generate moderate heat. HO T5 bulbs are available in all popular Kelvin Ratings and wavelengths, and are ideal for use in small to medium sized live planted or reef aquariums up to 24” deep. HO T5 bulbs should be replaced every 12-18 months. HO T5 bulbs are not interchangeable with standard output T5 light bulbs.