Besides skimmers, lighting has to be the most popular topic on the great wide inter-webs when it comes to reefing. And for good reason. There are an astounding number of options, and new ones hitting the market on what seems like a daily basis. These days it's mostly LED, although over the past year or two, both T5 and Metal Halide seem to be quietly sneaking back over people's tanks. Personally, I have run all three options over the years and have gotten a really good feel for the advantages and disadvantages of each, much of which is just personal preference. I'm not going to get into any kind of debate on what's better. What I would like to do is show you my current setup and maybe give you an idea of why I have settled on my current configuration. And it's important to remember, this is just one Every Day Reefer's experience.
As I mentioned above, I have long term experience with all three lighting options. So which have I settled on? All three! That's right. I've found there are positive (and negative) qualities of each, so let's go through them one by one.
Metal Halide (MH)
To make a completely unscientific statement, I have always felt that there is no other lighting option commonly available to the Every Day Reefer that better mimics the sun than MH. They seem almost as bright as the sun, they seem almost as hot as the sun, and a single bulb has the fullest, broadest spectrum of the three. When you look at the water, you get that shimmer just like with natural sunlight over shallow waters. You get the contrast but you also get plenty of light spread. The main issue people have with MH is the heat generated mostly by the bulbs, but even the ballast can get pretty warm. The second issue is the electricity needed not only to run the bulbs, but commonly a chiller is needed as well, and maybe even more air conditioning in your home. This all varies from setup to setup but generally these are some things to expect.
T5 Flourescent
These bulbs were meant to replace MH and/or VHO (T12). They promised less heat and less electricity. The big advantage for me, is increased light spread. These are the "softest" of the three options, and really spread the light out well. The downside for me, is that on their own, the look is too flat with no shadows and no shimmer effect. I like my shimmer and I like some contrast. I also find that you really need to have at least 6 bulbs in order to get a decent combo of colors. And trying to find the right combo of bulbs can get a little expensive and frustrating. But many people love the look of an all T5 lit reef, and I've seen some amazing ones with sps colors that are just unreal.
LED
The latest and greatest lighting technology not only for reef tanks, but freshwater aquariums, homes, commercial buildings, parking lot lighting, sports arenas, etc is LED and for good reason. With lower power consumption, less heat, and much longer life expectancy, it makes the most financial sense. The technology may cost a little more upfront but in the long term it can be a huge money saver in the right application. Another advantage for aquarium usage, is their penetrating power, wide array of available colors, and they are infinitely dimmable. Who doesn't like a smooth, ramping sunrise/sunset? And then there is the ultra fluorescent coral colors you get from the blue leds. No other lighting creates that blinding 70's black-light look.
Unfortunately, when it comes to aquarium lighting, LED may not be the golden boy it was originally touted to be. First, as mentioned above, it costs more to get started. Those with DIY skills have a big advantage in this area, but the majority of Every Day Reefers out there will be looking at off-the-shelf options, plug and play. Depending on the features of the fixture, LED can be quite the investment.
Second, and in my opinion the most detrimental aspect of LED fixtures (at the time of this writing) and without a doubt the most challenging obstacle for the LED fixture manufacturers to overcome is the fact that individual LED diodes are a pinpoint light source. Even if you clump a bunch of them together to form what is most commonly referred to as a "puck", you still end up with a very directional light source. In other words, LED has the worst light spread out of all three lighting options. The manufacturers have tried using "lenses" over the leds to help mix the colors together and soften/spread the light a bit, but it's not enough. If not using pucks, the other option is to spread the leds out across the face of the fixture. The more you spread them out, the more chance of you seeing individual spots of color in your aquarium, commonly referred to as the "disco" effect. Lenses can help with this to an extent, or more LEDs spread over the unit. But no matter what, if you hang one of the more popular LED fixtures over your tank that is reported to cover a 24" x 24" area next to a MH bulb in a proper reflector, you will see that the MH spreads the light more evenly over a larger area and the intensity is more evenly spread out across this area. LED will have extremely high PAR dead center and then this PAR will fall off dramatically as you go away from center. The "cone" effect. As your coral grow, they begin to shade themselves because the light is hitting one side and can't spread around to the other side. The only way to overcome this is to either raise the fixtures higher to help spread the light (but you lose intensity) or buy more fixtures. Buying more fixtures takes an already expensive startup cost and makes it more expensive.
Here is an example of what happens when your coral is not getting enough light spread under LED, and then the difference of just a few months of growth under the MH/T5 combo. Notice the much improved polyp extension/growth/color underneath, as well as the tighter growth pattern overall.
Third, the spectrum and intensity of these units is left to the consumer to figure out. With all that adjustability comes the responsibility or challenge of figuring out what looks good and more importantly what will grow your coral. I don't know about you, but this would be completely guesswork on my part. I'd rather pick out a proven MH bulb, throw it over my tank and know that if my coral aren't growing, the lighting is not the problem.
Today
So after trying all three lighting options over various tanks long term, I've settled on using all three. The idea is to use each type of lighting for it's advantages as a way to overcome the disadvantages of each. In my setup, I'm using MH as my main source of light. My midday spectrum, high intensity, growth bulb. I'm using three 250w Radiums which could be run on their own. They have a very crisp white look to them with a hint of blue. I'm running these for around 6.5 hours in the middle of the day. Radiums are one of those MH you just can't go wrong with. They look great, and they are known to produce pretty decent growth.
Then I run four 80w (60") T5 bulbs. The T5 are doing a few things. One, they fill in some shadows. Two, they extend my viewing period with less electricity and heat than the MH. Three, they let me make slight alterations to the overall color of my tank when all lights are on. Four, they let me simulate a dawn/dusk effect in the mornings and evenings. My current configuration is one ATI Coral+ which gives me a little more white light for growth when the MH are not on. Then I have one KZ Super Blue (similar to ATI Blue+) which adds some more of that crisp white/blue to the overall spectrum when all lights are on. It's also a pretty high PAR bulb. And finally, I run two Giesemann Super Actinics to help fill in the lower part of the spectrum.
Lastly, I run a 72" Build My LED "Super Actinic Reef Spectrum" led strip. It's the very first light to come on, and the very last to turn off. During this time I get those crazy fluorescent colors from my coral. And when all lights are on it adds just a little bit more blue to the overall spectrum. My total lighting period is extended for a little bit longer, and at a total of 100w at full power, it's not costing me very much at all.
Due to space constraints in my canopy, I decided to go with a compact fixture from Hamilton Technology, rather than individual reflectors... their 72" Cebu Sun. This takes care of the MH and T5. Then the BML LED strip is attached to the Cebu Sun with a couple of self-threading metal screws as seen in the pics below.
Lighting Schedule
LED - 9:30am to 10:30pm
T5 (two actinics) - 10am to 9:30pm
T5 (Coral+ and SuperBlue) - 10:30am to 9pm
MH - 1:30pm - 8pm
I hope this helps some of you in your quest for the perfect lighting setup. This has given me the best growth and healthiest coral, with the look that I prefer, but at the cost of using a bit more electricity. For me, this extra cost is worth it, and I'm lucky to live in an area where electricity isn't too expensive.