Lighting plays a very important role in the aquarium, more so than a  majority of people realize. In keeping fish in a “closed system” (fish tank), it is important that we recreate their natural environment as closely as possible. Lighting can be a major link between success and failure in keeping your fish aquarium.

The sun is the number one energy source of all living creatures. As aquarists or hobbyists, we must learn to recreate the sun’s energy (intensity, duration and heat) and put it to use in our aquarium. The sun’s intensity and duration do many things for us. First, it helps set and maintain the biological clocks (daytime/nighttime, long day/short day, breeding season) in all of our living creatures. Secondly, through a process called photosynthesis, it allows the growth of plants and algae in our aquarium, which are food for our fish and purifiers since many plants and algae fix (take up) many dissolved gases. The sun’s heat provides warmth for our cold blooded fish, which depend entirely on the sun for maintaining the proper temperature.

The light we put above our aquarium is important because it recreates the sun’s intensity and duration. Intensity is a term used to describe the strength of the light. It can be increased or decreased by raising or lowering and the quality of the light bulbs used. Duration or photoperiod is a term used to describe the length of time the light is on. Many biologists feel that photoperiod or duration is an important parameter in the successful breeding of many species. The average duration or photoperiod for most aquariums is light on for 12 – 14 hours, and darkness for 10 – 12 hours. Whatever photoperiods you decide on for your aquarium, remember those plants and algae, a necessary ingredient require a “dark period” in order to grow.