This article was updated on the 3rd October 2019.
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All forms of life in an aquarium environment require some sort of lighting, and this lighting affects its inhabitants. Whether it's fish, plants, or corals, the type and intensity of the lighting impacts their health, coloring, stress, photosynthesis, and reproduction.
Standard fluorescent and incandescent lighting are suitable for most aquariums. However, there is a demand for more advanced lighting technology for complex setups. This is especially the case with popular freshwater plant and saltwater reef aquariums.
To determine an aquarium’s optimum lighting, the light spectrum requirements of the specimens needs to be examined. These requirements are based on the conditions that they inhabit in the wild. For example, some inhabitants come from shaded regions where light is less abundant. Conversely, there are inhabitants that come from shallow, tropical regions where they are exposed to intense full-spectrum lighting for long periods of the day.
Currently, there are a number of lighting options available for aquariums. They include incandescent lighting, fluorescent lighting, compact fluorescent light, LED lighting, and metal halide lighting.
For decades, incandescent lighting has been a popular choice as it offers different colors and bulb strengths. The bulbs are also inexpensive, which makes them a very versatile light source for both large and small aquariums.
However, incandescent lighting generates a notable amount of heat. Therefore, proper ventilation may be required when using incandescent light bulbs.
The other disadvantage of using these lights is that the bulb life is short, and they are inefficient when a high lumen output is required for deeper aquariums.
This option is probably the best all-around lighting method to use for aquariums, and has become more common than incandescent bulbs. Fluorescent bulbs generate very little heat compared to incandescent bulbs and are inexpensive; especially considering their relatively long shelf-life.
Fluorescent light bulbs are long glass tubes that contain bits of phosphor. When an electrical current passes through the glass tube, the phosphor heats up and emits light. The amount of phosphors inside the glass tube governs the spectrum and intensity, which results in different colors.
There are three main forms of fluorescent bulbs, and these are classified according to their amp output. They are ‘regular’, ‘high’, and ‘very high’ outputs. A ballast is required for each fluorescent bulb, and they are designed to regulate electrical energy from power outlets to the fluorescent light bulb, which prevents them from drawing too much current.
To function properly, high output and very high output fluorescent bulbs require special ballasts and end-caps, which are different from the ballasts used on regular bulbs.
Additionally, to increase the overall lumens, it is common to mix fluorescent light bulbs with other bulbs, such as metal halide and power compact bulbs.
Power Compact Lighting
Power compact bulbs are commonly referred to as compact fluorescent lighting and are a new technology in the field of aquarium lighting.
Compared to traditional fluorescent light bulbs, compact fluorescent light bulbs generate considerably more light, use less electricity, and are smaller in size, which makes them very economical for long-term use.
These light bulbs are also known for their depth penetrations, which makes them suitable for use in deep aquariums.
LED (Light Emitting Diode) lighting is another new option in the field of aquarium lighting and is becoming increasingly popular. LED bulbs generate a light that penetrates deep water, and unlike fluorescent lights, the color spectrum remains consistent for the life of the bulb.
Another advantage is their size, making the bulbs suitable for all aquarium setups. A higher initial outlay can be expected to light an aquarium with LED bulbs. However, the running costs are significantly lower than other lighting options.
LEDs are available in a range of colors to sustain fish-only, plant, coral, freshwater, or marine tanks.
Metal Halide bulbs are high-powered bulbs and require special ballasts and reflectors. Metal halide bulbs are available in a range of different wattages, which determines the brightness of the light bulb. They are mainly used in saltwater reef tanks where corals, anemones, and clams are kept.
Unlike fluorescent light bulbs, metal halide bulbs offer a pinpoint source of light rather than spreading the light over the entire length of the tube. This also means that these light bulbs generate an intense amount of heat in one spot. To avoid overheating the tank, these light bulbs need to be suspended away from the water’s surface.