Choosing Aquarium Lighting for Your Tank

Part of creating the perfect habitat in your aquarium tank is choosing the right lighting.

There are a lot of components to your aquarium tank that you need to think about to keep your fish healthy and happy: water, filtration, plant life and more. One often overlooked aspect of keeping a proper fish tank is choosing the right aquarium lighting. Though it may seem to be of secondary importance, lighting is an essential consideration in the life of your fish.

There is a lot to consider when choosing aquarium lighting. Most tanks will feature overhead, or hood lighting, though some will feature additional lighting systems. Furthermore, there are various different types of lights to choose from. Here are some that are used often:

  • Incandescent Lighting: These bulbs are the most commonly used for lighting households and consist of a bulb with a glowing filament. They are not terribly useful for aquarium tanks, as they do not operate on a large spectrum or produce much heat. As such, they tend only to be used on small fish tanks. For these situations, though, incandescent bulbs offer several advantages. They are inexpensive, long-lasting, and come in many colors. They are also the only type of light that does not require a ballast.
  • Fluorescent Lighting: Fluorescent lighting is the most common and versatile type of aquarium lighting. It operates with a ballast, and consists of a tube-like bulb which provides light. Fluorescent lighting is inexpensive to buy and operate, but needs to be replaced often.


Fluorescent lighting comes in several varieties.

  • Standard fluorescent lighting is low-spectrum and produces little heat. These bulbs are ideal for freshwater aquariums.
  • Higher in spectrum are High Output (HO) and Very High Output (VHO) fluorescent lights which are usually used for saltwater aquariums, especially if the tank is deep. These bulbs operate with different ballasts than standard fluorescent, and produce more heat, often necessitating the presence of a water chiller
  • The last type of fluorescent lighting is power compact lighting, which is the most versatile type of fluorescent lighting system. This type of system uses multiple bulbs that, like HO and VHO lighting, produce lots of heat. They need to be replaced much less often, though, and are relatively energy-efficient. They also tend to be slightly more expensive than other fluorescent lights.
  • Metal Halide Lighting: This is the most expensive type of aquarium lighting, but also provides the most efficient light. These systems are best for aquarium tanks that require a lot of light, including tall tanks, reef tanks, and tanks with many plants. Metal halide bulbs have been shown to aid aquarium plants in photosynthesis and produce a very pleasant light in the water.


Because of the intense heat they produce, your aquarium may need a water chiller and a circulation fan to cool the air under the hood. Additionally, the lighting system should be separated by glass from the water. This reduces UV exposure and keeps the system from getting wet.

When choosing lighting, you need to think about more than just bulb type. One of the most important considerations is wattage. Generally, you will need 3-5 watts per gallon and multiple lights if your water is deeper than two and a half feet. If you have plants, and especially if you have a reef, your wattage needs to be even higher.