LED and LEP Reef Tank Lighting Gets Thumbs Up For Coral Growth
At this point, its pretty easy to see that LED lighting is becoming the norm for those either starting new tanks or those who are fed up buying replacement bulbs. Though many of us have “reported” good growth and coloration with LED’s, there have only been a handful of studies done to support this. Just last week, we saw a new study come out that actually tested and measured coral growth under both LED and LEP (Light Emitting Plasma) lighting.
What are LED and LEP?
We have done some writing on what LED’s are in previous articles, but here are the basics. On a chip, you have a “light emitting diode” that is activated by running a small electric current through it. The resulting light is colored on the chip itself and comes in a variety of shades from actinic blue, to daylight white, as well as some new colors that folks are experimenting with such as red, green, and UV. These colors are ALL being incorporated in some new lights that ReefNation is building as we speak. Stay tuned for more on that.
LEP or light emitting plasma is a light fixture which at first glance resembles traditional metal halide lighting. The main difference is that LEP’s run about 50% more efficiently than metal halide lights and their bulbs last about 3x as long. Here is a link to a nice description and a video on what these lights look like.
What Were the Findings of the Study?
During the study which was conducted in an aquaculture facility by Tim Wijgerde and his team, both LED and LEP lighting was used on the coral Galaxea fascicularis and growth was measured over a period of 69 days. The measurement that was used for the lighting in the experiment was irradiance. Without getting all scientific, irradiance can be thought of as light intensity for a given area. The good news is that both the LEP and LED lighting showed growth in the corals, with the LEP slightly edging out the LED overall for coral growth. It was noted in the study that water flow or lack there of in the case of the LED’s may have kept their growth rates a little on the low side.
What do these Findings mean to Aquaculture?
Like any study of corals that you read, it becomes very evident that there are just a ton of variables that can skew results. This experiment was no exception to that rule, however a uniform growth using these two types of lighting was the overall goal and seemed to be confirmed pretty easily. Looking at this study as someone who keeps corals, I understand that Galaxia is a pretty simple subject to use due to its availability and heartiness in captivity. Heck, you can have a pretty dirty reef tank and Galaxia will grow like a weed. In the future, I would love to see this study done on some Acropora and Montipora species so that we could perhaps draw a more broad conclusion about how these lights both affect growth and perhaps secondarily how different mixtures of LED colors will affect coral coloration.
Hats off to Tim and his team for getting the ball rolling with this experiment and we can’t wait to see what research is conducted in the future to keep pushing the envelop in coral lighting research.
What has been your experience with LED or LEP lighting?