Staggered Lighting - why?

Over the years, I've kept a number of reef tanks with different lighting, but for the past two years, I've tried something new with something not so new. My reef tank is lit with metal halide (MH) bulbs in Lumenbright pendants, and supplemented with VHO actinic lighting. So far, I'm sure that sounds pretty standard, if not a little pricey. It was totally worth it, as I'm about to explain.

The Lumenbright reflectors truly put out 300% more light than a standard reflector like the "batwing" or "spider" reflector. When I was about to upgrade to the better reflectors, I measured the intensity in various places in my reef with a PAR meter. One spot was in the center of the infamous Toadstool leather on the right side of my 280g reef. The old reflector, using a 250w 10,000K bulb with a magnetic ballast measured 144 on the meter. Once the new pendant was in place, the PAR measured 444 in the exact same spot.

With such a huge jump in PAR, I was sure my corals would be burned. Heeding the advice of Mike at Reef Specialty, I opted to run each light 2 hours a day. I had three, so I set them up so each one came on after the last one turned off so I could look at my reef for 6 hours a day. Each week, I would increase the timers 1/2 hour longer. It took about two months to ramp each bulb up to 6 hours a day. And in doing so, I grew used to looking at my tank without all the lights on at once. It wasn't an easy thing to swallow, but over time it grew on me. The lights click on one by one until by 3:30 p.m. each day, the tank is fully lit. By 7 p.m., the first light clicks off and within a few more hours the lights are off again. It actually looks and feels more natural to me.

Having the reef fully lit for 3.5 hours each day is what I call "high noon". In the image below, you'll see how the light phases work. I set up the camera and took pictures all day long to create this montage.



One of the perks of this method is that you don't use as much electricity, which many people are well aware of as they try to save money anywhere they can. Using better reflectors is key, because the reef gets a good burst of light for a shorter period. Additionally, these reflectors are hung higher over the tank, which helps avoid excessive heat issues. Without the heat, there's less reason for a chiller to run. Less electricity both in bulb use and chiller use is a boon for some. A real example would be if a hobbyist normally runs their MH bulbs 9 hours a day, this would be a 33% reduction in power consumption. 3 hours x 250w x 30 days = 22.5 kWh less than before. Add a chiller than usually runs at least 5 hours per day that now only runs perhaps 2.5 hours, and the savings is obvious.

Another perk is the space I have to work in my tank with the pendants hanging 12" off the top of my tank. This puts the bulbs at 18" off the water, and they are behind tempered glass because the pendants come that way to keep the reflective surfaces clean.

With the overlapping time periods of the bulbs, the corals still get some light even as the one overhead clicks off. It is a pleasing view as I gaze at some corals under the blue glow of the VHOs while a 10,000K bulb blasts another area at the opposite end. For those that like the actinic look, they can adjust the staggered lighting to suit their desires - providing enough light to get good growth and yet not have to see it all day long. The corals grew very well, actually better than my older lighting system.

So in a nutshell, more light, less heat, less electricity usage, and aesthetically pleasing. Are you willing to try this yourself?