LED lights that make corals pop with color

I wanted to talk about LEDs for a few minutes. I've had the Radion Gen 2 over my anemone cube (60-gallon aquarium 24" x 24" x 24") for the past 12 months. As a light, it functions perfectly. Is it the best fixture ever? My feelings are a tad mixed, and I'll discuss why. The light itself provides sufficient lighting for anemones, SPS, LPS, gorgonians, zoanthids and even a T. maxima clam. All seem to do quite well and have all grown as one might expect.




The fixture is sleek, clean, and silent. It always turns on when it should, and turns off as expected. With the Reeflink hooked up, EcoSmart Live (ESL) offers some nice light-menus to select from and I chose what seemed my best preference. Originally it was called Progressive Mode if I recall correctly, although that has since been renamed Radiant Mode. Also, I enabled Lunar Mode and set the daily schedule to 75% intensity. When I looked at my tank, it was fine. Nothing special, nothing offensive, just doing the job day in and day out without any drama. Did it justify the cost? Sometimes I wondered about that. The livestock did well.


Lunar Mode matches the moon's cycle. The first time I noticed it: the tank was glowing blue past the period the light should have cycled off, but... it was awesome! I was enamoured with the color, the way the anemone tentacles glowed like an underwater rave party. I stepped outside to look up and indeed there was a full moon shining brightly overhead. How cool is that, the moon and my light are aligned perfectly calendar-wise. The "overtime" (sports reference!) glow occurs about three days a month I'd guess because I've never bothered to track it. I'd actually love to see the tank like this all the time, but that's unnatural and odds are that spectrum wouldn't benefit the livestock. It's a very nice feature to look forward to, to be sure. Of course, the opposite of the lunar mode cycle is the new moon when it is quite dark outside. On that particular night, the Radion turns off a tad earlier than scheduled, so there were a couple of occasions when I'd run late feeding the reef to discover that tank was already in sleep mode, so to speak. That kind of bugged me, but I've adapted and try to be more aware. (If push comes to shove, I can manually turn the lights back on for the feeding and then back to the schedule a few minutes later.) Still, Lunar Mode made me appreciate the Radion a whole lot more. I was seeing more value in my purchase.




Last week, after 51 weeks of running the tank at 75% intensity, I thought about how the anemones were stretching up towards the light and perhaps they'd like to receive more. I set the light to 80% intensity with ESL which took less than 60 seconds to accomplish. For the next few days, I was continuously enthralled by the way the livestock looked, almost like it was in High Definition compared to before. I kept staring at the anemones, and wondered how a mere 5% more light could starkly change their appearance. And once again, I was very happy with my light fixture all of a sudden. It's like my appreciation comes in waves.




I tend to be more patient than most, and all of the above leads me to this: Could it be that hobbyists are dialing in their lights to hit that "look of perfection" only to harm those corals due to that lack of acclimation? Maybe if they'd wait longer (and I mean many months) before increasing the light's brightness, the corals could accept the light and would even prepare for an additional burst of intensity at a future date? This is so different from the days of metal halides where you knew to reduce the light period with a brand new "hot" bulb, ramping it up over the next few weeks and then leave them as is for about 9-10 months before repeating the cycle anew since the aged bulbs were losing PAR. Daily, I read so many threads by hobbyists trying to maintain corals under LEDs and the dominate theme is always that they need to reduce the intensity significantly. Maybe they need to just provide "light" for now, and later aim for "perfect light"...


I have to say it's enjoyable that even after all these years in the hobby, I'm still musing over things such as these.

I have three different LED light fixtures in use. The Radion as described above. I have an Evolution LED fixture that has been running since 2011 that I believe is past its prime because nuisance algae has been an ongoing issue in the frag tank. The third LED fixture by UniqueLED Lighting lights the refugium zone, and has done a great job for the past 3.5 years. There are at least a dozen well-known LED makers on the market currently, and a huge group of cheaper knock-off fixtures that are constantly being made available to aquarists everywhere. Without a doubt, some are better made than others - but for the average hobbyist and especially newer hobbyists, they won't have it long enough to know if it was a good purchase or a poor one. As corals perish, their passion wanes and they abandon the hobby in disgust, OR they keep upgrading their lights, spending more and more to acquire better features and leaving previous fixtures in their wake. Be that as it may, is there an ideal routine or schedule that will provide the right amount of light to your reef's livestock? Most definitely.

Most people will select a light period for their tank that spans a specific set of hours that match their own routine. Often they will set the first hour with actinics (blue light) only, then add the rest of the lighting for the duration of the day, and finally wrap up with an hour of blue light again. With LEDs, you now have greater flexibility because not only can you pick a specific spectrum of light you prefer, but you can switch them instantly with your computer or smartphone with zero delay. There are benefits to this flexibility, but let's go back to what happens in nature. Ever been camping before? You wake up as the sun begins to rise, and you start the campfire and enjoy some quiet time eating breakfast as the campsite begins to come to life with more and more light. A few hours later, the sun has risen high in the sky and shadows shrink as the rays come straight down. This high-noon period is a daily occurrence, but have you really grasped that point? The sun continues to move across the sky as the afternoon elapses, and you note the sunlight lessening as you enjoy the cool air whilst relaxing with a beverage. Dusk happens, and by then you'll need a lantern and a campfire to see your way for the rest of the evening. Similarly, the sun moves over the reefs providing intense light for a few hours, but for the rest of the time it's just daylight, until nightfall.

Our reef tanks need that same type of light - not a full-blast-all-lights-on-now type environment. I've advocated this for many years, suggesting a 3.5 hour "high noon" period with all the lights on, with a more gradual ramping up and later ramping down of the aquarium lighting. My other article about staggered lighting depicts how nicely this works most especially over a bigger aquarium with multiple fixtures. In the case of the Radion fixture, here's one daily schedule pre-programmed via EcoSmart Live.


Let's put some real numbers to this graph to display the schedule that has worked beautifully for the past year. My lights turn on at 1 p.m. daily and by 10:20 p.m. they are dark, unless moonlighting is cast via lunar scheduling handled by the software. Why did I choose these particular hours? Daylight already spills into the room each morning, plus I'm rather nocturnal. I prefer to enjoy looking at my aquariums during the afternoon and evenings.



Notice in the graph above how the light's intensity grows over a period of hours, with the peak of the day at 5:40 p.m. High Noon would be roughly the 4:10 p.m to 7:10 p.m. time slot, then it tapers off again. This copies nature's span of daylight, and is so much easier to program compared to the on-off of metal halides, VHOS, and T5 bulbs.

If you have LEDs over your tank now, or are going to be installing some in the near future, consider if they are programmable in a similar fashion. If they are not, perhaps you can enable banks of lights at a time, building up to the crescendo of the day, then reverse the amount of lights to attempt to mimic the ramping up and down of daylight and blues (and other colors available). For example if you have the ability to wire up rows of blues and white pucks, perhaps run two pucks, then in a couple of hours four pucks, then later six or eight pucks, then back to four, and then back to two again. Same principle, just not as sleek as the higher end light packages available today. If your lights provide a software package to create a custom light period, program it like the example above. Or if your aquarium's controller has a dimming module, you can edit the code to program your lights that way.

The main point is that it's totally fine to have high definition eye-popping colors that make your mouth hang open, just don't do that all day long. Provide your livestock with some necessary 10,000 Kelvin light when you are at work or away running errands, unless you are like me and you like seeing corals in natural lighting. Run those crazy blues when you know you'll be near the tank to enjoy the view and appreciate all your hard work growing those gems into colonies. Employ a gradual light period that imitates the sun overhead, and remember that corals need to rest and are completely fine in total darkness all night long. If you like moonlights, run them for a couple of hours, then turn them off. Fish and other invertebrates aren't like us, they don't need a night light to avoid slamming a shin into a coffee table in the middle of the night. If you are asleep, let your reeflings sleep too.

Additional Reading:
Staggered Lighting - http://www.reefaddicts.com/content.p...d-Lighting-why