The light that an aquarium needs is tricky – and really depends on the type of life that exists in it. A saltwater aquarium for example, requires different lighting from the lighting designed for freshwater aquariums. To find out what kind of lighting is appropriate for your *specific* kind of fish, you can ask the store from which you purchased it. But generally, the following advice applies to all kinds of fish and other aquatic creatures even though aquarium lighting is more beneficial to its plant life than it is to the life that happens to swim around in it.
Kinds of Light
You’re probably already familiar with incandescent aquarium lamps. But fluorescent lights can work just as well as long as they use naturally colored bulbs and encourage plant growth. In addition, fluorescent lights are less expensive than incandescent aquarium lamps and they don’t use as much energy nor do they put off as much heat. Although aquarium tops’ (hoods) primary function is to prevent fish from jumping out of the tank and to reduce water evaporation, most of them have a built-in lighting system.
Appropriate Amounts of Light
All fish thrive with lighting that follows the “per gallon” rule. This rule suggests that lighting should put out no more than two and a half watts per gallon. One way that you can tell if you’re exposing your fish to too much light is to look for high levels of algae growth. Algae loves light and if you notice a lot of it in your aquarium, it might be the result of over-exposure.
You can also monitor the growth of your plants to determine if your lighting strategy is successful. If they don’t seem to grow as expected, you might need to increase light.
Grow lights encourage the growth of not only the plants and fish in your aquarium (something you want), but they also encourage the growth of algae (something you definitely don’t want). However you can combat algae growth by placing an aquatic snail inside your tank.
A “Light” Schedule
Generally, your fish should be exposed to light at least twelve hours every day but again, the specifics depend upon the type of fish and aquarium that you have. This schedule benefits your aquatic plants as well since they use this light to absorb carbon dioxide in your tank and release oxygen to your fish!