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News & Reviews Article
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Lighting Choices for the Reef and Planted Aquarium |
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| Last Updated |
2009-12-08
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Lighting Choices for the Reef and Planted Aquarium
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With all the lighting choices available to the hobbyist today, it can be confusing and difficult to make the best choice for your particular aquarium. Years ago, the rage was the use of VHO (Very High Output) fluorescent lighting.
Then Metal Halide lighting moved in and took over the market. Eventually, more affordable Power Compact (PC) fixtures became
popular. These fixtures provided intense lighting at a fraction of the cost of Metal Halides and with less cost in operating the fixture. Now
emerging in popularity is the HO (High Output) T5 fluorescent fixtures. These fixtures are becoming more and more affordable, cost little to
operate, generate little heat and the replacement bulbs are inexpensive compared with the cost of replacing Power Compact lamps (the cost of replacing PC lamps is often close to the cost of a
brand new fixture).
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In the future, we are likely to see affordable LED (Light Emitting Diode) fixtures for lighting our reefs and planted aquariums. For now though, these fixtures remain out of the price range for most aquarists (a 48� Solaris fixture retails for nearly $3000.00). EXPENSIVE and the company is now out of business. |
As technology advances and production increases, these LED fixtures may eventually replace all types of aquarium lighting. Here are some interesting facts about the Solaris LED fixtures. The expected life of the LED lamps is 50,000 hours. That means if you were to run the fixture for 12 hours per day, the lamps would not need replacing for 11 years!!! There is practically no heat that reaches the aquarium
from the light fixture. LED fixtures use 40% less energy than a 400 watt Metal Halide fixture. Still, the cost is likely to keep most folks just
wishing for one of these LED fixtures.
For now, let�s talk about the HO T5 fixtures that are now available for both planted and reef aquariums. Though most have concentrated on
watts per gallon, one should instead consider the Lumens produced by the lamp. A 150 watt metal halide lamp produces about 15,000 lumens which is approximately 100Lpw (lumens per watt). A 65 watt PC lamp produces about 4400 lumens which is approximately 68 Lpw. Compare those numbers with a single 54 watt HO T5 lamp which produces 4700 lumens which is approximately 87Lpw.
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| Though the metal halide clearly produces more visible light (lumens), the fixture is expensive to operate each month and generates much more heat. The lamp temperature of a single 400 watt metal halide bulb is about 1200 degrees compared with a T5 lamp of only 77 degrees! Both metal halide lamps and power compact lamps have extreme color shifts as they age. After one year, metal halide lamps decreased anywhere from 22% (67K) to 50% (20K) in intensity. Power Compact |
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lamp manufacturers suggest replacing these lamps every 12 months. We find these lamps shift in color spectrum after about 10 months when operated at 10-12 hours per day.
Though the reef organisms appear healthy even after this time, the visible light from the lampappears much more yellow in color. Though this is mainly an aesthetic issue, we have also seen more issues with problematic algae when this occurs. Heat is a big factor with degrading power compact lamps. Never run these lamps if the cooling fan in the fixture is not operating. T5 lamps run cool (about 77 degrees) and tend to hold their spectrum better than both PC and halide lamps. The efficiency of T5 lamps over the aquarium greatly depends on the reflector used in the fixture. A quality reflector will direct all the light down into the aquarium making the lamps most effective. T5 HO lamps should be replaced after about 25,000 hours of operation.
The lumen maintenance (how well a lamp maintains its light output over time) of a T5 HO lamp is 95% compared with a metal halide lamp at 75%. T5 HO lamps cost about 30% less to replace than PC lamps and about 70% less than a quality Metal Halide lamp. T5 HO fixtures are the least expensive fixture to operate when compared with the PC and Halide fixtures. With all of this information, we suggest using the T5 HO fixtures when possible. Aquariums that are deep (over 25�) should still consider the use of metal halides over the T5 fixtures as the choice lighting when keeping SPS corals. As for power compact fixtures, we are moving toward the T5 HO fixtures for the reasons listed in this article.
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