Alex Phelps: How and Why to Use LED Lights in Your Aquarium

Whether you’re in a fancy restaurant or the dentist office, there’s no denying that aquariums bring a certain amount of serene beauty to a space. For this reason, and because installing and maintaining aquariums has become more affordable, the DIY aquarium movement is on the rise. And with so many custom design options available, it’s easy to see why hobbyists and professionals alike often refer to aquatic environments as “living art.”

Alexander Phelps is a Los Angeles-based aquaria specialist. He is a former product specialist for Aquatop and is currently starting his own custom aquatic consultation firm, Bio-Topic. He believes that among many important factors, like filtration, symbiotic habitats and nutrients, lighting is a key component for both a healthy and beautiful aquarium.

“Lighting is important for one of two reasons, based on the application. Either you are trying to dramatically illuminate your aquarium for decorative effect, or you are using lighting to support photosynthetic life, AKA plants and coral,” says Phelps.

For both applications, Phelps believes LED lights to be the far superior choice above any other lighting type. Read on to find out Phelps’ useful tips for both decorative and photosynthetic aquatic lighting. (Keep in mind all lighting applications for aquariums should take place outside of the water, above or next to the tank, and should be water resistant due to condensation that can occur on the lights.)

Decorative Lighting

Don’t Overspend

“You don’t need to spend a lot of money on decorative lighting, since you’re not looking for LEDs that will support life. Use lower wattage fixtures like strip lights, and make sure they’re water resistant,” says Phelps.

Get Colorful
“Color-changing LED lights are very popular in aquatic environments these days. Most people are using LED lighting to change the mood setting, with a whiter color during the daytime and a moonlight effect at nighttime, achieved using purple and blue lights. You can use RGB LEDs to create any type of under water scenery,” says Phelps. A moonlight effect can be seen in the image above, which depicts a tank designed by Phelps.

Dim the Lights
“Use dimmable LEDs so you don’t blind your fish! A good rule of thumb is that if it’s too bright for you to look at, it’ll be too bright for your fish,” says Phelps.

Daylight Shimmer
Another huge decorative benefit of using LED lights is that they create what aquarium specialists call “daylight shimmer,” or a beautiful ripple effect in the water. “Daylight shimmer is created by point source lighting, which means lots of light from a single, focused source. Halogen lights also create daylight shimmer, but they use a ton of energy and also put out a lot of heat, which can affect the health of your aquarium. The other alternative, fluorescent lights, doesn’t create daylight shimmer because it isn’t a form of point source lighting,” says Phelps.

Photosynthetic Support

UV Lights
“If you’re looking for lights that will help support the life of living plants and coral, you want to choose LEDs that offer ‘usable light,’” says Phelps. According to Phelps, usable light does not refer to visible light or brightness, but instead to light in the blue or UV range of the spectrum, which is what all plant life uses to create chlorophyll A and B, the food that allows them to live and grow. The most popular LEDs for this application are “3 watt LEDs that offer a PAR (Photosynthetically active radiation) between 400 to 700 nanometers. PAR is the amount of usable light put out by a single source,” says Phelps. Try LightsWorldLED’s flexible ultraviolet LED strip light

Reduced Heat and Electricity Costs
The traditional lighting system for aquariums used to be metal halogen lights, which used tons of energy and also emitted so much heat that the aquarium required a whole separate refrigeration system. “There is so much heat transference to the water with halogen lights that you have to install a chiller to constantly run cold water back into the tank. The electricity costs are really high. With LED lights, you’re eliminating not only the energy costs of the lights, but also of the chiller,” says Phelps. “It’s important for any ecosystem to maintain a stable temperature—if not, certain organisms could die, or you could get overrun with algae.”

Healthier Ecosystems and Reduced Replacement Costs
When light is supporting life in your tank, it’s important to make sure that light maintains a consistent spectral output. “Many bulbs are hand selected for specific spectrums, but the problem with halogen or fluorescent bulbs is that over the life of the bulb, their light spectrum shifts. If over time you see a decline in the spectral output of the bulb, you’re going to see a decline in the growth of your ecosystem,” says Phelps.

“Either you’re having to replace your bulbs every 9 months, which is expensive, or you wait too long and risk shocking your photosynthetic life by changing the light spectrum too drastically when you do replace it,” says Phelps. LEDs, on the other hand, have a life span of 50,000-80,000 hours, and remain much more consistent in their spectral output throughout their lifespan. “You only have to replace them every five years or so,” adds Phelps.

“Aquariums are so cool because you get to create your own little world,” says Phelps. But with great power comes great responsibility, as the saying goes. And it looks like the most responsible aquarium owners are using LED lights for every application.

Visit our Aquarium Lighting project page for more aquarium lighting photos, examples product recommendations.