tacocat
05-20-2005, 02:48 PM
Lighting
Lighting is perhaps one of the most discussed topics in reefkeeping. Why? Powerful lighting is required for keeping most sessile reef creatures. For clarity’s sake, let’s call them corals. It has only been a relatively recent discovery that corals are actually symbiotic animals. Although they look like plants, they are actually animals, but inside of their tissue, they house zooanthella. Zooanthella are microscopic algae. They live in the coral (otherwise they become plankton) for protection and in return provide the coral with energy. Often times, the zooanthella can provide all of the nutritional need for its host organism. In fact most corals don’t have to eat if there is enough lighting available.
In order to keep most corals alive, a high output lighting system is usually employed. Most of the corals found in the hobby were obtained or originated from tropical or equatorial regions where sunlight is most intense. Furthermore, many of these creatures come from shallow waters. It is easier for divers to collect from shallower waters.
Since the creatures come from areas of high light intensity, it is best to provide them the same in the captive environment. This can be accomplished by using several different types or combinations of lamp systems available to aquarist today. These are Normal Output fluorescent lamps, Very High Output fluorescent lamps, Power Compact fluorescent lamps, T-5 fluorescent lamps, and Metal Halide Lamps. These lamp systems can be found in industrial applications as well. For the aquarium hobby we use lamps with a Kelvin rating of 6500K or higher (more on this later). This is to promote coral growth and inhibit nuisance algae growth. Most industrial bulbs are 5500K or less which promotes algae growth. So you can obtain your system from an industrial application, but be sure to use the correct aquarium hobby bulbs.
All of the lighting systems used in the hobby require a ballast to fire the bulbs. A ballast is basically a transformer that converts the household electrical supply into a usable energy source for the lamp. A ballast basically controls electrical current. All of these systems consist of a ballast which plugs into a wall, mounting hardware, and the bulb. All of them should incorporate some kind of ventilation system.
Normal output or NO lamps can be found in most pet stores, and if you have a 4ft long tank, at the local Home Depot as well. These NO lamps are usually 40w or less. This can be an economical method to keep soft corals zoos and other low-light requiring corals. At one time, I used 4 40w daylight deluxe (6500K) bulbs on NO ballasts to keep softies and some LPS. Be sure to use enough lamps and use the bulbs with a Kelvin rating of 6500K or greater. I wouldn’t recommend this system due to the availability and low cost of stronger lighting systems.
Very High Output or VHO lighting was the staple lighting system many years ago. They look identical to NO bulbs. VHO bulbs are every similar in function to NO bulbs, except they require a stronger ballast, but they burn several times brighter than NO bulbs. Although the technology is old, there have been many improvements in ballast design. In fact the Icecap ballasts can drive NO, VHO, PC, and overdrive T-5 bulbs. Unfortunately, there are only a few bulb manufacturers remaining, and the selection of bulbs isn’t too great. Of course they are more expensive than NO bulb systems.
Power Compact or PC lighting cam about in the 1990’s they are thinner (most are “U”shaped) than NO and VHO bulbs, and uses only one socket (instead of two like NO bulbs) which makes installation a snap. They are similar in intensity to VHO bulbs in a watt per watt comparison. They are very common, come in many configurations, and offer the most bulb selection for fluorescent lamp systems.
T-5 lighting is the newest kid on the block. T-5 probably offers many advantages that the other lighting systems don’t have (with the exception of VHO’s actinic capability). T-5 bulbs are basically PC bulbs cut in half. They are called such because T-5 is the socket size of the bulb. T-12 is the socket size of VHO/NO bulbs. T-5 bulbs also use up less power than a comparable VHO/PC bulb, half a PC bulb, half the power. Even though they use less power than most systems, they still generate a lot of heat. In some cases they may even crack glass….cough. Like NO/VHO bulbs, T-5 bulbs use two sockets. Because they are thinner than a standard NO bulb, more bulbs can be installed into a given area, of course power consumption goes up. Most T-5 setups include a mirror that wraps around the bulb. This mirror takes up more room, but it is highly recommended that T-5 bulbs be run with the mirror. The mirror virtually doubles the T-5 bulb’s intensity, a concept we will revisit later. T-5 lighting has a very good bulb selection. T-5’s future looks bright.
Metal Halide lighting or MH lighting for short is the most intense lighting available at this point in time. Metal Halide lighting shares more in common with household screw in bulb than it does with fluorescent lighting systems. MH systems do require ballasts to operate. In fact it is one ballast to one bulb. Double and triple ballasts are available. MH lighting in function is similar to a household bulb in that it is point source light. This means all of the light emanates from one spot versus along the full length of a fluorescent bulb. In an MH bulb, the filament is a small glass capsule filled with metal (mercury I believe). During ignition, the mercury is vaporized and the excited gases and metal glow. The fact that MH is point source causes the flickering appearance in a reeftank and it makes object appear more three dimensional.
MH systems come in two types, Single Ended and Double Ended. Each type requires different ballast. An SE ballast will not run a DE bulb. A DE ballast is more powerful than an SE ballast. In fact many people use DE (or HQI) ballasts to overdrive SE bulbs. SE bulbs look just like regular light bulbs but larger. In fact they act like them too. DE systems are identical in function except the bulb is charged from both ends. The bulbs themselves are thinner than SE bulbs. If one examines them side by side, one will realize that the internals of an SE bulb look identical to a DE bulb. In fact the large glass structure of the SE bulb is in fact a UV shield. The DE bulb eliminates the UV shield to achieve its small size. As a result, the DE bulb must be used in a pendant setting the pendant incorporates a UV shield and a reflective mirror.
The pendant in fact is the key to DE’s wide acceptance. In the case of PFO and Reef Optix III pendants, the reflector is optimized around the DE bulb. The DE bulb’s small size allows a very efficient reflector to fit around it. In fact, the PFO AND RO III pendants cause a 250w DE lamp to be nearly as intense as a 400w SE bulb without a reflector. The drawback is that DE setups don’t have the spread of SE setups.
Reflectors are also available for SE lighting systems. The spider type reflectors even the playing field between SE and DE setups. In fact the Lumenarc III reflector is produces as much intensity as a PFO or RO III reflector, but it is very large. I don’t recommend running any MH system without an optimized reflector.
Lighting is perhaps one of the most discussed topics in reefkeeping. Why? Powerful lighting is required for keeping most sessile reef creatures. For clarity’s sake, let’s call them corals. It has only been a relatively recent discovery that corals are actually symbiotic animals. Although they look like plants, they are actually animals, but inside of their tissue, they house zooanthella. Zooanthella are microscopic algae. They live in the coral (otherwise they become plankton) for protection and in return provide the coral with energy. Often times, the zooanthella can provide all of the nutritional need for its host organism. In fact most corals don’t have to eat if there is enough lighting available.
In order to keep most corals alive, a high output lighting system is usually employed. Most of the corals found in the hobby were obtained or originated from tropical or equatorial regions where sunlight is most intense. Furthermore, many of these creatures come from shallow waters. It is easier for divers to collect from shallower waters.
Since the creatures come from areas of high light intensity, it is best to provide them the same in the captive environment. This can be accomplished by using several different types or combinations of lamp systems available to aquarist today. These are Normal Output fluorescent lamps, Very High Output fluorescent lamps, Power Compact fluorescent lamps, T-5 fluorescent lamps, and Metal Halide Lamps. These lamp systems can be found in industrial applications as well. For the aquarium hobby we use lamps with a Kelvin rating of 6500K or higher (more on this later). This is to promote coral growth and inhibit nuisance algae growth. Most industrial bulbs are 5500K or less which promotes algae growth. So you can obtain your system from an industrial application, but be sure to use the correct aquarium hobby bulbs.
All of the lighting systems used in the hobby require a ballast to fire the bulbs. A ballast is basically a transformer that converts the household electrical supply into a usable energy source for the lamp. A ballast basically controls electrical current. All of these systems consist of a ballast which plugs into a wall, mounting hardware, and the bulb. All of them should incorporate some kind of ventilation system.
Normal output or NO lamps can be found in most pet stores, and if you have a 4ft long tank, at the local Home Depot as well. These NO lamps are usually 40w or less. This can be an economical method to keep soft corals zoos and other low-light requiring corals. At one time, I used 4 40w daylight deluxe (6500K) bulbs on NO ballasts to keep softies and some LPS. Be sure to use enough lamps and use the bulbs with a Kelvin rating of 6500K or greater. I wouldn’t recommend this system due to the availability and low cost of stronger lighting systems.
Very High Output or VHO lighting was the staple lighting system many years ago. They look identical to NO bulbs. VHO bulbs are every similar in function to NO bulbs, except they require a stronger ballast, but they burn several times brighter than NO bulbs. Although the technology is old, there have been many improvements in ballast design. In fact the Icecap ballasts can drive NO, VHO, PC, and overdrive T-5 bulbs. Unfortunately, there are only a few bulb manufacturers remaining, and the selection of bulbs isn’t too great. Of course they are more expensive than NO bulb systems.
Power Compact or PC lighting cam about in the 1990’s they are thinner (most are “U”shaped) than NO and VHO bulbs, and uses only one socket (instead of two like NO bulbs) which makes installation a snap. They are similar in intensity to VHO bulbs in a watt per watt comparison. They are very common, come in many configurations, and offer the most bulb selection for fluorescent lamp systems.
T-5 lighting is the newest kid on the block. T-5 probably offers many advantages that the other lighting systems don’t have (with the exception of VHO’s actinic capability). T-5 bulbs are basically PC bulbs cut in half. They are called such because T-5 is the socket size of the bulb. T-12 is the socket size of VHO/NO bulbs. T-5 bulbs also use up less power than a comparable VHO/PC bulb, half a PC bulb, half the power. Even though they use less power than most systems, they still generate a lot of heat. In some cases they may even crack glass….cough. Like NO/VHO bulbs, T-5 bulbs use two sockets. Because they are thinner than a standard NO bulb, more bulbs can be installed into a given area, of course power consumption goes up. Most T-5 setups include a mirror that wraps around the bulb. This mirror takes up more room, but it is highly recommended that T-5 bulbs be run with the mirror. The mirror virtually doubles the T-5 bulb’s intensity, a concept we will revisit later. T-5 lighting has a very good bulb selection. T-5’s future looks bright.
Metal Halide lighting or MH lighting for short is the most intense lighting available at this point in time. Metal Halide lighting shares more in common with household screw in bulb than it does with fluorescent lighting systems. MH systems do require ballasts to operate. In fact it is one ballast to one bulb. Double and triple ballasts are available. MH lighting in function is similar to a household bulb in that it is point source light. This means all of the light emanates from one spot versus along the full length of a fluorescent bulb. In an MH bulb, the filament is a small glass capsule filled with metal (mercury I believe). During ignition, the mercury is vaporized and the excited gases and metal glow. The fact that MH is point source causes the flickering appearance in a reeftank and it makes object appear more three dimensional.
MH systems come in two types, Single Ended and Double Ended. Each type requires different ballast. An SE ballast will not run a DE bulb. A DE ballast is more powerful than an SE ballast. In fact many people use DE (or HQI) ballasts to overdrive SE bulbs. SE bulbs look just like regular light bulbs but larger. In fact they act like them too. DE systems are identical in function except the bulb is charged from both ends. The bulbs themselves are thinner than SE bulbs. If one examines them side by side, one will realize that the internals of an SE bulb look identical to a DE bulb. In fact the large glass structure of the SE bulb is in fact a UV shield. The DE bulb eliminates the UV shield to achieve its small size. As a result, the DE bulb must be used in a pendant setting the pendant incorporates a UV shield and a reflective mirror.
The pendant in fact is the key to DE’s wide acceptance. In the case of PFO and Reef Optix III pendants, the reflector is optimized around the DE bulb. The DE bulb’s small size allows a very efficient reflector to fit around it. In fact, the PFO AND RO III pendants cause a 250w DE lamp to be nearly as intense as a 400w SE bulb without a reflector. The drawback is that DE setups don’t have the spread of SE setups.
Reflectors are also available for SE lighting systems. The spider type reflectors even the playing field between SE and DE setups. In fact the Lumenarc III reflector is produces as much intensity as a PFO or RO III reflector, but it is very large. I don’t recommend running any MH system without an optimized reflector.