Lighting is often a hotly debated topic on Reef Central, because there are people who have had success or failure with each different type of lighting system used in the hobby. The most important consideration for reef tank lighting lies in choosing a lighting system based on the requirements of the animals that we wish to keep. While many reef keepers are concerned with the appearance of their reef tank, their main concern should be the health of the light requiring animals that they are attempting to keep. There are many different types of lighting systems available to the reef keeper. They can be simple fluorescent lights ballast, newer compact fluorescent lights or metal halide lighting. All of these lighting systems have advantages and disadvantages, but each may be successfully used to light a reef tank.
There are two types of fluorescent lights ballast available for fluorescent tubes: 1) core and coil ballasts and 2) electronic ballasts. The common ballasts that come with the standard NO and VHO bulbs and strip lights are core and coil ballasts. They are somewhat heavy, produce some heat and use more electricity than electronic ballasts. The electronic ballast does initially cost more, however, the savings in electricity and minimal heat output is, generally, well worth the initial cost. Electronic ballasts weigh far less than the core and coil ballasts, which allows more versatility in placement options. One particular model of electronic ballast, made by IceCap,™ Inc., can power both NO, VHO and power compact tubes in various combinations with up to four bulbs. It is claimed that the longevity of the fluorescent tubes is better when using the electronic ballast over the core and coil type ballast, but many reef keepers replace the tubes every six months anyway due to a shift in spectrum as the bulb ages.
There are quite a few different color spectrum options available in fluorescent light ballast tubes, with the most common being full spectrum, actinic and 50/50 (which is a combination of both). The most popular fluorescent tube color spectrums are: the daylight, 6500 Kelvin bulb that is normally recommended for SPS or clam tanks when enough tubes are used to create the proper intensity. The next is the combination Actinic and daylight bulb (a 50/50), which is equivalent to a 10000-Kelvin bulb and is well suited for soft coral and LPS tanks.