Lighting is an essential component in your aquarium to ensure your fish remain healthy and happy. The right amount of lighting provides several important advantages, including:
- Reducing water evaporation
- Helping to maintain a consistent water temperature
- Reducing household pollutants
- Enhancing the color of your fish and the attractiveness of your aquarium
- Providing photosynthesis, which is necessary for live plants
While it’s not necessary to keep the light on for extended periods, it’s important to understand how much light your fish actually require.
Choosing the Right Lighting for Your Aquarium
There are two main types of lighting available for your aquarium: fluorescent tubes and incandescent bulbs. While incandescent bulbs are generally less expensive than fluorescent tubes, they tend to produce more heat and less natural light. As a result, incandescent bulbs are better suited for smaller tanks, typically 10 gallons or less.
For larger tanks, fluorescent lighting is a better choice because it provides more natural light with less heat. Additionally, fluorescent light fixtures tend to be more flexible, making it easier to select the right light for your aquarium.
If your aquarium has live plants, you should use a full-spectrum fluorescent bulb to best simulate the sunlight. If you need more intense lighting to support plant growth, you can increase the wattage. For example, heavy plant growth can be achieved by using at least 60 watts of lighting for every 12 inches of tank length. While fluorescent lights can be more expensive to purchase initially, they are cheaper to operate in the long run.
When selecting lighting for your tank, consider what is inside it. For instance, reef tanks require more lighting than tanks that contain only fish. Planted freshwater tanks also need more lighting, and live rock tanks, which contain photosynthetic animals, should be treated similarly to reef tanks and thus require more lighting. For reef tanks, it’s best to choose high-intensity aquarium lighting, such as compact fluorescent lighting, VHO lighting, or metal halide lighting.
Here’s a breakdown of different types of aquarium lighting:
Compact Fluorescent Lighting: Provides bright, efficient, and cool light with a low operating cost, producing less heat than many other intense light sources.
VHO Fluorescent Lighting: Offers super bright and long-lasting light, making it ideal for reef aquariums.
Metal Halide Lighting: Known for providing high heat with a wide spectrum range, this lighting is suited for reefs and freshwater aquariums deeper than 24 inches. In some cases, a chiller may be necessary to counteract the intense heat produced, especially if the room temperature can’t be balanced to offset it.
The size and depth of your tank also play a role in choosing the appropriate lighting. Typically, 1.5 to 6 watts of lighting per gallon is recommended. For deeper tanks, additional lighting may be necessary since light doesn’t penetrate water very well. Metal halide lighting is a great option for tanks deeper than 20 inches, as it provides more concentrated light.
Fish-Only Aquariums: These tanks will do well with a standard fluorescent lighting system, providing between 1 to 2 watts per gallon.
Freshwater Planted Aquariums: Aquariums with both live plants and fish will thrive with a standard fluorescent lighting system, providing between 2 to 5 watts per gallon.
Saltwater Reef Aquariums: These tanks, which house invertebrates, corals, and fish, will require a more advanced lighting system, such as power compact, VHO, or metal halide lighting. Plan for between 4 to 8 watts per gallon for aquariums that are 24 inches deep or less. If you only house corals or invertebrates that require lower light levels, you can relax these wattage requirements somewhat.
