LED lighting is becoming a popular alternative way to light aquariums, however many LED fixtures may not be ready to grow corals in reef aquariums.
Lack of the correct variety in light spectrum and less water penetration can reduce coral and plant growth, both of which are things to consider when thinking of buying LED lighting.
“If you want to get the quality of a fluorescent, with the same type of spectrum, you’d have to buy a more expensive LED,” Ian Higby, an aquatics specialist at Pet World Inc., Lawrence, Kan.
Vinton Ebling, owner of Paradise Aquatics, Overland Park, Kan., said a full spectrum LED lighting fixture can cost as much as $600, where a comparable metal halide lighting setup will cost about $350.
Metal halide and fluorescent lighting are the most common type of lighting used over coral reef aquariums because both types of lights can provide a full color spectrum of light. Many LED lighting fixtures commonly sold at local fish stores usually include only white and blue colored LEDs.
White and blue LEDs in combination can make a light that looks natural to humans, but corals need more of variety in color spectrum to grow.
Lighting that as closely duplicates the sun, not necessarily light that is most pleasing to us, is important for all life, although more noticeably for corals and plants, Carl Strohmeyer, Founder of American Aquarium Products, said on his company’s website.
Low-end LED fixtures usually use less expensive LEDs that are designed to look bright to humans rather than using LEDs designed specifically for water penetration.
Ebling said he has noticed that corals showing signs of decreased growth in some aquariums using LED lighting.
“There used to be white on the edges,” Ebling said, referring to a white hue on the edges of a red cap montipora coral, an indication of growth, “now it doesn’t look like it’s growing at all.”
David Burr, owner of Vivid Aquariums, Canoga Park, Cal., conducted a long-term test comparing full spectrum LED lights to metal halides. Burr placed twelve 140 watt Ecotech Radion LED fixtures over half their 800 gallon aquarium and four metal halide fixtures, totaling 2,800 watts, over the other half. Burr configured the LED fixtures to mimic the color and spectrum of metal halide lights.
Depending on the type of coral, growth and coloration vary between LED and metal halide lighting, Burr said, but some corals seem to color and do better under metal halides.
LEDs are a great way to supplement florescent or metal halide lights to make certain colors appear brighter, Higby said. Higby uses a Marineland Blue Accent LED fixture to supplement his florescent lighting over his reef aquarium, but there’re not enough by themselves to grow corals.
“For tanks over 30 inches in specimen placement, the metal halide is still generally the best available light,” Strohmeyer said.