The health of your aquarium inhabitants can often be directly attributed to the type of light fixture employed over your particular aquarium setup. If the correct spectrum and intensity of light is not provided, the survival rate of your photosynthetic aquarium plants, corals, or invertebrates will be poor. When selecting your aquarium lighting system, your goal should be to duplicate natural conditions. Thanks to recent advancements in lighting technology, this has become an easier task.
Keep in mind when selecting your aquarium lighting system that all aquarium light fixtures generate heat. Typically, the more powerful the lighting system, the greater the cooling requirements are likely to be. Regardless of the size or type of your lighting system, your aquarium should be located in a temperature-controlled room to help minimize unnecessary temperature fluctuations.
Fish-only Aquariums: With fish, artificial plants, driftwood, reef rock, and/or decorations
Typical Lighting System: Standard fluorescent, T-5 fluorescent, or LED light fixtures.
Generally speaking, the lighting requirements of a fish-only aquarium is primarily an aesthetic one, meaning you can choose any aquarium light fixture that best suits your budget and preference. However, be sure to select a light fixture designed specifically for aquarium use, as household light fixtures may not have the necessary water-proofing to accommodate moist or harsh aquarium conditions.
Freshwater Planted Aquariums: With fish, live plants, driftwood and/or decorations
Typical Lighting System: Standard fluorescent, T-5 HO fluorescent, Metal Halide/HQI, or LED light fixtures.
Most freshwater aquatic plants available on the market originate from river shallows in Central and South America. Though the water there is often stained or murky, these aquatic plants still experience full-spectrum light. Therefore, no matter which specific species of plants you plan to acquire, be sure to employ aquarium light fixtures with full-spectrum output designed to promote live aquatic plant growth. These specialized light fixtures typically emit light heavy on the red spectrum and are commonly referred to as “plant lights”.
Lighting systems designed for live plants typically generate more heat than general-purpose, fish-only light fixtures. If necessary, raise the light fixture slightly above the cover to provide extra space to promote better air circulation. A small cooling fan can also be used to efficiently dissipate heat away from the fixture.
Marine Reef Aquariums: With fish, invertebrates, corals, and live rock
Typical Lighting Systems: T-5 HO, Metal Halide/HQI, or LED light fixtures.
Photosynthetic corals and invertebrates rely on light to obtain a major portion of their nutrition. However, the amount of light required varies dramatically from species to species. In the wild, many SPS corals are found at depths between 15 and 65 feet where the light is extremely intense. In contrast, many LPS (large polyp stony) corals are found at deeper depths, below 65 feet where light intensity is much more subdued.
Aquarium lighting systems designed for corals with higher light requirements typically generate a substantial amount of heat. It is important to provide some sort of supplemental cooling as excessive heat buildup can decease useful life of your reef aquarium light fixture. A fan can be used to disperse excess heat buildup, but an environmental temperature control system (HVAC) provides a better solution. In extreme cases, an aquarium water chiller may be required to counteract rising water temperatures caused by radiant heat absorbed directly by the water.
Of course, you can minimize cooling requirements by choosing corals and invertebrates that require low levels of light, as well as non-photosynthetic invertebrates. By doing so you can employ aquarium light fixtures that emit less light (and heat) while still satisfying the photosynthetic needs of your corals.
One of the most significant improvement in recent aquarium lighting systems include the use of electronic ballasts resulting in efficient bulb (lamp) startup for less heat generation and extended usable life. Aquarium light bulbs (lamps) have also evolved, offering a wider range of light spectrum and intensity output to provide greater setup options. Most importantly, these newer aquarium lighting systems can now closely replicate natural lighting that organisms experience in the wild.
Energy Efficient Lighting Options
T-5 High Output (HO) Fluorescent Systems: High light output, compact size - the most advanced fluorescent lighting available! At only 5/8" in diameter, T-5 HO fluorescent lamps emit almost twice the brightness of standard fluorescent lamps. In addition to their brightness, you can also fit more of these slim bulbs into the same amount of space.
LED (Light Emitting Diode) Light Fixtures
Once considered a "newcomer" to the world of aquarium lighting, LED light fixtures are now regarded as the norm for most hobbyists. However, LED’s are still subject to confusion and misconceptions. LED technology employs a radically different approach to light generation. LEDs emit light as energized or exited subatomic particles pass through a semiconductor material. This distinct process of light generation called electroluminescence requires FAR LESS energy and subsequently generate less heat to produce brilliant light for a truly energy-efficient choice to aquarium lighting.
When concerned with supporting photosynthetic aquatic life, hobbyists should refer to the PAR values of the LED light fixture. PAR or Photosynthetically Active Radiation designates a specific range of the light spectrum (between 400 and 700 nm) that photosynthetic organisms utilize during photosynthesis to produce food and energy.
Many manufacturers of aquarium LED light fixtures include PAR information as part of their literature. However, due to the relative complexity of accurately representing light fixture PAR values and a lack of standardization, not all manufactures will provide PAR information the same way. When referring to PAR values to determine LED suitability for your particular aquarium setup, keep in mind that PAR values vary at different depths and distances from the light source. In other words, a single LED fixture will have multiple PAR value readings capable of supporting different species with different light requirements based on how close or how far the coral or plant is placed from the LED light source.
Therefore a "one size fits all" approach to understanding LED fixtures provides a true disservice to these innovative light fixtures. Maximize your LED experience by rethinking light in a three dimensional manner and know that PAR output of your LED fixture can be used to your advantage through thoughtful placement of livestock and easily augmented by employing additional LED fixtures.
Replicating natural lighting conditions for your aquarium inhabitants greatly increases both their survival and growth rates and enables you to recreate a more realistic ecosystem. When selecting your lighting system, be sure to evaluate both the initial and operating cost. Consider selecting fixtures that use electricity frugally and will not require frequent bulb (lamp) changes. It is usually worthwhile to pay a bit more for those with lower operating and maintenance costs.