Tropical fish are conditioned to love light. Their natural environment would have the brightness of a tropical sun during the day, and the deep darkness of night. Tropical fish lighting is required to help maintain your fish in their healthiest state and to increase the brilliance of their color.
Older aquariums often came equipped with a single screw in the bulb socket. These sockets were intended for having an aquarium light which was of the proper power and provided the proper spectrum of light. The first problem which many un-knowledgeable fish owners created was by replacing the bulb with a standard incandescent light. Suddenly there is too much brightness and far too much heat.
Today the best advice in tropical fish lighting is to use fluorescent light strips. They produce less heat and provide the proper spectrum of light. Make sure to replace your light strips every 6 to 9 months to keep them producing the best quality of light. As the gases in the tube dissipate the spectrum of light narrows providing less efficient lighting.
Tropical fish lighting should be cycled on and off for day and night. You can accomplish this by simply turning it on in the morning, and off when you go to bed, or you may want to get a timer so you do not need to worry about it. A timer will help on setting up a variable lighting time for summer and winter times, too. The breeding cycles of many fish are predicated on the amount of daylight time.
Your tropical fish lighting is not only for the benefit of your fish but for the benefit of your aquarium plants, too. Since you are using artificial light it is important to have live plants. They help use up the light and deter the growth of algae. If you do not have enough live plants algae is almost certain to grow rapidly making your tank a green mess.
Sometimes the biggest challenge in fish tank lighting comes from the tank itself. Most tanks include a cover which gives you room for only one light. Often this one light is not adequate to fully illuminate the tank. You can then choose to add additional light strips over the tank, or to the rear of the tank just below the outer edge of the tank glass.
One word of warning on lighting. It is a real balancing act to get enough light to have a bright tank, but not enough to create an algae bloom. If you keep having too many algae growing to consider reducing the wattage of the bulbs or add more live plants to the tank.
Throw away the idea of having a naturally lit tank. Tropical fish lighting is a necessity to reduce the growth of bacteria, increasing fish colors, spurring breeding, and helping your aquatic plants to grow. Choose high-quality fluorescent fixtures and they will last the life of your tank.