Arofanatics Fish Talk Forums - View Single Post

10-01-2005, 04:50 PM

Continue from previous....

Rules of Thumb

Watts/gallon rule: 1.5 to 3 watts/gallon for low light, 3 to 5 watts for medium light, 5 to 7 for hi light up to 10 for the most demanding acropora sps., anemones and clams. This rule has been around for many years and has become questionable with the advent of CFL and MH lighting.

Different lighting systems vary greatly as to output per lamp:

50 Lumen/watt - NO Fluorescent 300w would produce 15,000 Lumens, loosing 10% at half-life of 10,000 hrs.
56 Lumen/watt – VHO Fluorescent 300w would produce 16,800 Lumens, loosing 30% at half-life of 4,000 hrs.
85 Lumen/watt – CFL Fluorescent 300w would produce 25,500 Lumens, loosing 30% at half-life of 6,000 hrs.
75 Lumen/watt – Metal Halide 300w would produce 22,500 Lumens, loosing 20% at half-life of 5,000 hrs.
85 Lumen/watt – HQI Metal Halide 300w would produce 22,500 Lumens, loosing 20% at half-life of 5,000 hrs.

VHO turns out to be only modestly more efficient than NO, but is preferred because of the number of tubes that can be packed into a canopy.
CFL are nearly as efficient as MH but lack the hot spot intensity because the output diffused over a linear dimension, a problem common to all fluorescent bulbs.
MH is a point source producing high efficiency and intense output.
Lumen/watt, spectrum drift and useable lifespan can vary by more than 25% depending on bulb manufacturer and type of ballast used.
All of these bulbs produce pretty much the same waste heat. It is just more or less concentrated by the bulb dimensions

Changes in tank setup have also added problems. A 250-gal tank with a 6-inch sandbed is really a 180 gal tank only 18 inches deep.

In order to obtain the maximum Lumen output all bulbs need to be installed in individual, parabolic, specular reflectors. These reflectors will increase output by as much as 270%. Having multiple lamps in one reflector increases bulb heating and restrikes. This will lower lumen output output and shorten bulb life.

Yet another rule, specific for MH lighting, is on lamp for every 2 feet of tank or 4 square feet of surface area. The bulb wattage is determined by tank depth – 175w for up to 18 inches, 2 50w for 18” to 36”, 400w for 24” to 36”, and 1,000w for over 36”. This seems to be a very vague guideline.

A more recent rule is Lumen/square foot of tank water surface: 1,500 to 2,500 Lumens/sq. ft for low light corals, 4,000 to 5,000 for medium light corals and 7,00 to 8,000 Lumens/ sq. ft. for light loving corals clams, etc. Sounds familiar, doesn’t it?

Even this rule has some problems. If you light the 180 gal tank by this rule the proper selection would be 4 – 250w MH (10 CFL) or 80,000 Lumens (7,000/sq. ft.). Remember, though, a MH is a point source. The square foot directly below the light will actually see 12,000 lumens – a bit much even for anemones. Mid light corals will go on the bottom third and don’t try low light corals except on the bottom. I won’t even mention the electric bill for cooling the tank and running the lights.

The final, actually the first, consideration is tailoring the light output to the corals. What corals do you plan on keeping? Low light mushroom, cryptic sponges, soft coral, LPS, SPS. All have their own needs and will perish if ignored. Too much light will kill as surely as too little.

One solution is to limit your specimens to those with the similar lighting requirements. Unfortunately, most aquarists use a gardening approach, picking their animals by personal preferences as to color, shape or even strangeness.

Conclusions

Can we create our diverse coral garden without sacrificing the health or life of these animals? Happily, with a little ingenuity and a lot of attention to detail, the answer is yes; you don’t even need to take out a second mortgage.

Starting with a 250-gal 96”Lx24”H x18”W tank we build up the substrate 6 inches. This gives a tank depth of 18”. Since the greatest variety of corals come from around 20 feet our main lighting should be 10,000K MH with supplementation by 6,500K fluorescent. 100% fluorescent is too diffuse and uniform for our garden.

The hot spots from 250w MH are way too intense for most corals in the upper levels of our tank Instead, why not use that that point source characteristic to our advantage. Lets go with 175w MH, or better yet, 150w 10,000K HQI. Now the center square is getting 7,800 Lumens while the tank bottom sees 1,950 Lumens. The pendants will be mounted 10” above the water and the entire canopy shielded with tempered glass. Now, all those different specimens collected from different depths can be happy living together.

Let’s go a little farther. Add 4 – 95w 6,500K CFL fixtures to even out the lighting and give a spectrum boost to the shallow water corals. With all these lights we can start staging on and off times to simulate sunlight conditions. When all is done you should be averaging less than 600 watts per hour and still have a 12 hour photoperiod. You’re using all electronic ballasts, of course. Now everyone can be happy. Even when the electric bill arrives!

Final Thoughts

Everyone acclimates their animals to the new water environment, slowly changing their water to prevent shock and stress. How many of us consider acclimating to light. When you take home a new coral it has been at least three different places as well as dark bags for many hours while traveling
around the world. You place it carefully in your tank and turn on the stage spotlights . The poor thing never had a chance!

Most coral are pretty flexible but they need time to adapt. This can take up to 2 weeks. Meanwhile they need protection. This is not a problem in the beginning. When the tank has been up for a year or so, you’re going to stress out everyone by playing with the lights. Set up the reef to have areas at the edge of the MH lighting squares with shading or even a cave. You can use this as a nursery to slowly bring your new acquisition into the light.

An acclimation tank is another solution. It doesn’t have to be fancy or even be running all the time. When you are planning for a new animal, fill a 10 gal with water from the main tank, throw in a power head, heater and several pounds of live rock and you’re all set. The light doesn’t have to be fancy either – a 150w brite white incandescent flood hung as a pendent will do – you’re acclimated for light intensity.

I chose 150 HQI pendants because they produce the same lumens as a 175 standard MH and have almost the same Par. Inexpensive electronic ballasts are available which run cool, produce about 10% more light, extend the bulb life and color stability. They also consume only 10watts more than the bulb giving them an operating efficiency of 95%.

HQI bulbs should be changed at about 60% of rated life - 4,800 hours – every 18 months – one at a time please! Raise the pendant to 18” during the initial 100-hr burn in.

There is a lack of data on aquarium bulbs that looks like an industry wide conspiracy. No manufacturer supplies specs as to lumens (initial and mean), Par or lifespan. They routinely supply them for every other bulb they make. Even the spectrum numbers are arbitrary. According to Sanjay, the actual bulb temperatures are often two or three thousand degrees off. AB produces a bulb designated 10,000K but actually runs at 13,000K initially. They kept the old designation for marketing. As far as you and the LFS know it’s a 10,000 K when you buy it.

HQI bulbs generate significant UV-A, B and C. A shield is needed to Reduce the UV-A and eliminate the UV-B and C. You want a shield anyway to protect against splashes and spray (HQI and MH bulbs operate at 3,000deg.F and can explode violently). Tempered float glass does the job very effectively.

All lighting needs to be vented to remove heat emitted by the bulbs and ballasts. Several methods are used. Passive venting in the fixtures and small fans pushing and pulling air in the canopy. This will, of course, move some of the heat away from the water surface. Unfortunately it requires you to run air conditioning to remove that heat from the house. BTW air should not be blown over a metal halide bulb – it both changes the spectrum and shortens the life of the bulb.

The most cost-effective method is to enclose all lighting in a canopy that is vented to the outside. If vented to the roof the system can be entirely passive All shields can be removed from the individual lights and replaced by one sheet of tempered LOW E glass on the bottom of the canopy. This glass will eliminate both UV emissions and at least half of the infrared.

There are three new technologies that look promising in the near future. LED, Fiber Optic and CCFL. Both have a unique advantage of putting light below the waterline without heat or infrared. This would allow all bulb output to be in the water column. Fiber Optic looks more promising and cost effective at the present time

Note: There may be some formatting or typo error.

10-01-2005, 04:50 PM	#3
Maculosus Guest Posts: n/a	Continue from previous.... Rules of Thumb Watts/gallon rule: 1.5 to 3 watts/gallon for low light, 3 to 5 watts for medium light, 5 to 7 for hi light up to 10 for the most demanding acropora sps., anemones and clams. This rule has been around for many years and has become questionable with the advent of CFL and MH lighting. Different lighting systems vary greatly as to output per lamp: 50 Lumen/watt - NO Fluorescent 300w would produce 15,000 Lumens, loosing 10% at half-life of 10,000 hrs. 56 Lumen/watt – VHO Fluorescent 300w would produce 16,800 Lumens, loosing 30% at half-life of 4,000 hrs. 85 Lumen/watt – CFL Fluorescent 300w would produce 25,500 Lumens, loosing 30% at half-life of 6,000 hrs. 75 Lumen/watt – Metal Halide 300w would produce 22,500 Lumens, loosing 20% at half-life of 5,000 hrs. 85 Lumen/watt – HQI Metal Halide 300w would produce 22,500 Lumens, loosing 20% at half-life of 5,000 hrs. VHO turns out to be only modestly more efficient than NO, but is preferred because of the number of tubes that can be packed into a canopy. CFL are nearly as efficient as MH but lack the hot spot intensity because the output diffused over a linear dimension, a problem common to all fluorescent bulbs. MH is a point source producing high efficiency and intense output. Lumen/watt, spectrum drift and useable lifespan can vary by more than 25% depending on bulb manufacturer and type of ballast used. All of these bulbs produce pretty much the same waste heat. It is just more or less concentrated by the bulb dimensions Changes in tank setup have also added problems. A 250-gal tank with a 6-inch sandbed is really a 180 gal tank only 18 inches deep. In order to obtain the maximum Lumen output all bulbs need to be installed in individual, parabolic, specular reflectors. These reflectors will increase output by as much as 270%. Having multiple lamps in one reflector increases bulb heating and restrikes. This will lower lumen output output and shorten bulb life. Yet another rule, specific for MH lighting, is on lamp for every 2 feet of tank or 4 square feet of surface area. The bulb wattage is determined by tank depth – 175w for up to 18 inches, 2 50w for 18” to 36”, 400w for 24” to 36”, and 1,000w for over 36”. This seems to be a very vague guideline. A more recent rule is Lumen/square foot of tank water surface: 1,500 to 2,500 Lumens/sq. ft for low light corals, 4,000 to 5,000 for medium light corals and 7,00 to 8,000 Lumens/ sq. ft. for light loving corals clams, etc. Sounds familiar, doesn’t it? Even this rule has some problems. If you light the 180 gal tank by this rule the proper selection would be 4 – 250w MH (10 CFL) or 80,000 Lumens (7,000/sq. ft.). Remember, though, a MH is a point source. The square foot directly below the light will actually see 12,000 lumens – a bit much even for anemones. Mid light corals will go on the bottom third and don’t try low light corals except on the bottom. I won’t even mention the electric bill for cooling the tank and running the lights. The final, actually the first, consideration is tailoring the light output to the corals. What corals do you plan on keeping? Low light mushroom, cryptic sponges, soft coral, LPS, SPS. All have their own needs and will perish if ignored. Too much light will kill as surely as too little. One solution is to limit your specimens to those with the similar lighting requirements. Unfortunately, most aquarists use a gardening approach, picking their animals by personal preferences as to color, shape or even strangeness. Conclusions Can we create our diverse coral garden without sacrificing the health or life of these animals? Happily, with a little ingenuity and a lot of attention to detail, the answer is yes; you don’t even need to take out a second mortgage. Starting with a 250-gal 96”Lx24”H x18”W tank we build up the substrate 6 inches. This gives a tank depth of 18”. Since the greatest variety of corals come from around 20 feet our main lighting should be 10,000K MH with supplementation by 6,500K fluorescent. 100% fluorescent is too diffuse and uniform for our garden. The hot spots from 250w MH are way too intense for most corals in the upper levels of our tank Instead, why not use that that point source characteristic to our advantage. Lets go with 175w MH, or better yet, 150w 10,000K HQI. Now the center square is getting 7,800 Lumens while the tank bottom sees 1,950 Lumens. The pendants will be mounted 10” above the water and the entire canopy shielded with tempered glass. Now, all those different specimens collected from different depths can be happy living together. Let’s go a little farther. Add 4 – 95w 6,500K CFL fixtures to even out the lighting and give a spectrum boost to the shallow water corals. With all these lights we can start staging on and off times to simulate sunlight conditions. When all is done you should be averaging less than 600 watts per hour and still have a 12 hour photoperiod. You’re using all electronic ballasts, of course. Now everyone can be happy. Even when the electric bill arrives! Final Thoughts Everyone acclimates their animals to the new water environment, slowly changing their water to prevent shock and stress. How many of us consider acclimating to light. When you take home a new coral it has been at least three different places as well as dark bags for many hours while traveling around the world. You place it carefully in your tank and turn on the stage spotlights . The poor thing never had a chance! Most coral are pretty flexible but they need time to adapt. This can take up to 2 weeks. Meanwhile they need protection. This is not a problem in the beginning. When the tank has been up for a year or so, you’re going to stress out everyone by playing with the lights. Set up the reef to have areas at the edge of the MH lighting squares with shading or even a cave. You can use this as a nursery to slowly bring your new acquisition into the light. An acclimation tank is another solution. It doesn’t have to be fancy or even be running all the time. When you are planning for a new animal, fill a 10 gal with water from the main tank, throw in a power head, heater and several pounds of live rock and you’re all set. The light doesn’t have to be fancy either – a 150w brite white incandescent flood hung as a pendent will do – you’re acclimated for light intensity. I chose 150 HQI pendants because they produce the same lumens as a 175 standard MH and have almost the same Par. Inexpensive electronic ballasts are available which run cool, produce about 10% more light, extend the bulb life and color stability. They also consume only 10watts more than the bulb giving them an operating efficiency of 95%. HQI bulbs should be changed at about 60% of rated life - 4,800 hours – every 18 months – one at a time please! Raise the pendant to 18” during the initial 100-hr burn in. There is a lack of data on aquarium bulbs that looks like an industry wide conspiracy. No manufacturer supplies specs as to lumens (initial and mean), Par or lifespan. They routinely supply them for every other bulb they make. Even the spectrum numbers are arbitrary. According to Sanjay, the actual bulb temperatures are often two or three thousand degrees off. AB produces a bulb designated 10,000K but actually runs at 13,000K initially. They kept the old designation for marketing. As far as you and the LFS know it’s a 10,000 K when you buy it. HQI bulbs generate significant UV-A, B and C. A shield is needed to Reduce the UV-A and eliminate the UV-B and C. You want a shield anyway to protect against splashes and spray (HQI and MH bulbs operate at 3,000deg.F and can explode violently). Tempered float glass does the job very effectively. All lighting needs to be vented to remove heat emitted by the bulbs and ballasts. Several methods are used. Passive venting in the fixtures and small fans pushing and pulling air in the canopy. This will, of course, move some of the heat away from the water surface. Unfortunately it requires you to run air conditioning to remove that heat from the house. BTW air should not be blown over a metal halide bulb – it both changes the spectrum and shortens the life of the bulb. The most cost-effective method is to enclose all lighting in a canopy that is vented to the outside. If vented to the roof the system can be entirely passive All shields can be removed from the individual lights and replaced by one sheet of tempered LOW E glass on the bottom of the canopy. This glass will eliminate both UV emissions and at least half of the infrared. There are three new technologies that look promising in the near future. LED, Fiber Optic and CCFL. Both have a unique advantage of putting light below the waterline without heat or infrared. This would allow all bulb output to be in the water column. Fiber Optic looks more promising and cost effective at the present time Note: There may be some formatting or typo error.