Several years ago, I set up my reef tank with “spider” reflectors. Since that is the way it came and many people used them, I felt reasonably sure they would continue to do a good job. Within a few months, a friend from DFWMAS recommended that I change their orientation so that they ran perpendicular instead of parallel with the tank. And he was right!
Instead of seeing a band of light that moved across my reef as I rolled the light rack back and forth out of my way, everything was more evenly lit. And all was well. My reef grew, the tank seemed bright, but I didn’t really have any facts to support any decisions I made when it came to lighting. My experience was merely what I’d observed based on coral growth.
A few people in the hobby were doing PAR (Photosynthetically Active Radiation) measurements of various bulbs, charting that information and trying to help us better understand how light penetrates into our tanks. At many marine conferences, Sanjay Joshi spoke about his PAR testing with a variety of reflectors, bulbs and ballast configurations. The one thing that continued to stand out in my mind was that I needed better reflectors.
The one thing I couldn’t accept was the price. A “spider” reflector costs about $35 online, while the Luminarc reflector was about $120 each. I just couldn’t wrap my brain around the idea of paying so much for a reflector that was merely metal riveted together. There were a few DIY threads that showed what some people were able to fashion together, and other threads about how you could buy inexpensive aluminum sheet metal and polish it to a high degree of brilliance.
The other issue was that I really liked my rolling light rack, and the new reflectors were huge. They not only cancelled out the rack, but took away all the space I had to work in my tank. Last year at MACNA, I saw a new reflector that looked like a shiny salad bowl, called a Lumenbright. I burst out laughing, thinking who would buy such a thing? Six months later, after seeing a few of them in use, I found myself wanting some after all.
At the same time, I kept thinking about how nice it would be to test the PAR of my tank both with the old reflectors and the new ones. That way, not only would the lighting be upgraded, but also I would know for a fact what was really spilling into the tank.
One thing was for certain – if I was going to spend this much money on new reflectors, there would be a piece of glass between them and the water to keep them clean and in new condition. Over the years, various fish have splashed the reflectors I had, shattering bulbs and ruining the reflective surfaces. A friend of mine was kind enough to lend me his Apogee PAR meter while I transitioned from the old to the new.
I had to build a holder for the sensor, which was easy. I heated up some spare acrylic and screwed the sensor in place.
While testing, I made sure to leave the pumps running as I wanted to know what the corals actually receive on an hourly basis. The numbers on the meter bounced around due to the rippling surface, but after watching the meter for about 20 seconds, it was possible to average out the most consistent number. Measurements were taken at the surface, 1” beneath the surface, as well as at 6”, 12”, and finally down at the substrate at 24” beneath the water’s surface. Below you’ll see the first set of numbers. The bulbs and reflectors were salt-spattered, and those MH bulbs were 9” off the surface of the water.
The first thing I noted was that the magnetic ballast on the right side of my tank was half the intensity of the electronic ballast on the left side. This could have been due to the very long power cord that was included both before the ballast as well as between the ballast and reflector. They came this way, and it never even occurred to me that the ballast could work better with shortened cords. The additional wiring provides resistance. I had to return the meter before I could re-test that ballast with a 6’ cord, unfortunately.
The next round of tests was done with clean reflectors and brand new bulbs. I also tested with new 12,000K Reeflux bulbs to compare against the 10,000K bulbs. Additionally, I tested the PAR after placing a 20” x 20” sheet of ¼” tempered glass between the bulb and the tank, to see how much loss would occur. And finally I tested once more with a sheet of ¼” clear acrylic. I was told that the glass would filter out a lot of the lighting, in effect wasting what the new reflectors would provide. If the Lumenarc reflectors were truly 300% better than spider reflectors, I figured I could take a small hit due to the glass and still be ahead of the game. Based on the PAR numbers, it told me that the glass wasn’t nearly the obstacle others had predicted. The difference was negligible.
The numbers were interesting. You can read about all the various tests on this page. Now that I had all those numbers documented, it was time to take out the old light rack and replace it with the huge Lumenbright reflectors. These cost $135 each, including the glass. You can buy them for less without the glass, but I don’t see the point. Each pendant weighs about 20 lbs due to the glass and the black outer shell, but they look great and I’m very happy with that purchase. However, how good are they? Any difference in PAR? How does the light spread? Was it worth the $400 I spent?
In a nutshell, this is a great upgrade for anyone that has been wondering about this topic for a while. You can still use the same ballasts and bulbs, and you’ll save money in the process. I’ll explain why in a little bit. Due to intensity of the Lumenbright reflectors, they need to be suspended higher than we normally install our reflectors. (Click HERE to read a thread about reflectors). Mine are set up so that the bulbs are 18” from the water. Once that was done, I could continue with the testing.
As you can see, the values are significantly higher, and that is with the lights installed at twice the height of my original fixtures. Just looking at the Toadstool leather numbers, PAR increased from 110 to 444! Due to this increase of light intensity, each MH ballast’s timer was reprogrammed to light my tank for only four hours a day, instead of the normal nine hour photo period. Having a PAR meter to measure the light gave me the knowledge to know what to do instead of merely guessing what might be right. This avoided bleaching corals, or worse.
Weekly, I increased the photo period of the lights by 30 minutes, until they were on for six hours a day. The lights are staggered on over an 11 hour day (including the actinics). In this way, my tank is viewable for a longer duration without the need to run the lights as long. Shaving off three hours per bulb daily (2700 watts total), saves $11.42 per month or $137 annually. My reef looks just as good, if not better, with an increase of SPS growth in the past two months running the lights less than before. Here is the lighting schedule I’ve been employing.
Lighting
10,000K ReefLux (right) 1:00 p.m. to 7:00 p.m.
20,000K Radium (center) 2:15 p.m. to 8:15 p.m.
10,000K ReefLux (left) 3:30 p.m. to 9:30 p.m.
VHO lighting 11:00 a.m. to 10:00 p.m.
Because the lights are mounted so high off the water, heat isn’t nearly an issue. And I have plenty of room when working in the tank or taking pictures, without risk of burns or splashing the bulbs. The reflectors are warm to the touch.
By using the PAR meter, you can measure what individual corals are receiving, as seen above. This can be beneficial when acclimating new frags to the tank, or to find out if the bulb needs replacing, or if the reflector needs to be adjusted in height to extend the life of the bulb. If you own dimmable ballasts, the PAR meter can be used to make minor adjustments to match the PAR evenly and avoid hot spots or overdriven bulbs. The Apogee PAR meter costs about $325, and it can be re-calibrated by the manufacturer. Hopefully more hobbyists will purchase this useful tool to fine-tune the lighting needs of their reef systems.
For more information about these reflectors and what they can do:
http://reefkeeping.com/issues/2008-06/review/index.php
Additional information is also available at my site:
http://www.melevsreef.com/par_readings.html