I think I have the best solution for the lights but I need some help with admittedly basic information that I don't have. I have a lighting engineer who is part of my project team for the house. He has been talking to the Philips lighting engineers. They have been asking questions that I don't have the answers to, so I thought I might ask them here. The solution that I am looking at has the following characteristics:
ColorReach Powercore (housing)
Each fully aimable panel is ( H X W X D inches) 20.5 X 28.9 X 4.8 .
Each panel has two parts split evenly into ..........
Lumens 5200+ for the RGB LED
Lumens 1777 for the white light at 6500K
The RGB can throw light 500 ft.
There is no PAR information so I bought a single fixture to test with.
I will eventually get six panels. This lighting is capable of infinite dimming while maintaining colour temperature or varing colour temperature while maintaining brightness levels.
Beam angles 8 / 13 / 23 / 40 / 63 deg. 5 / 17 deg asymmetric lens.
designed for dry, damp, wet locations.
Questions are............
1. What is the impact if these lights do NOT offer light in the UV or IR frequency range?
I will have managed UV light in the fish room as part of the CL system.
2. Is the PAR measurement the only relevant measurement as far as coral health is concerned?
3. What differences in light requirements are there for fish vs corals? I realize fish can move and corals can't, for the most part.
Any feedback from knowledgable sources will be greatly appreciated.
Peter
How many watts per individual bulb/light point? The trend is toward higher wattage to provide more shimmer and shadows similar to the sun or at least MHL. Current mass produced LED fixtures with multiple points of light look eerie and clinical/fake like fluorescent light.
What are the dimensions of the fixtures? It seems tall 20.5"? Usually LED's are low profile 3"ish.
There are no known negative aspects to a lack of UV, or conversely benefits to having it, but in my unpopular opinion natural conditions should be replicated and UV does readily exist on natural reefs. Corals develop UV protection (mycosporine-like amino acids/MAA's) as sun block from the harmful UV rays of the sun. Reef fish have these same MAA's in their mucous. These were originally believed to be pigmented but are now known to be colourless. The zooxanthellae (symbiotic algae) within the coral's tissue are a light brown or drab green colour and do not require UV to our collective knowledge. This article and the series by Dana Riddle covers the subject of lighting and coral colouration.
http://www.advancedaquarist.com/2009/1/aafeature1
PAR is the biggest single lighting parameter you need to monitor. It will indicate if your bulbs are old and if they are adequate in the first place. PAR is basically the quality and intensity of light that is required for photosynthesis. LUX is the intensity reading that includes the higher nanometer (nm) light that is easily recognized by the human eye as being "bright". These readings are good for testing bulb life but do not indicate the hidden PAR generated by the light.
The other consideration is coverage, as LED tends to cover a smaller spotlight area compared to MHL or natural sunlight. Home & office use LED lamps are starting to use 7 watt multichip LED clusters.
http://shop.humanscale.com/family.cfm?groupid=87 and there are even 100 watt LEDs used in the aquarium trade now.
http://econlux.de/2010/
Your tank is shallow so lighting is not as challenging with regard to penetration, diffusion and intensity.
There are two ways of looking at the lighting issue. One way is to find out what corals appear to require for growth, health and colouration, then create those conditions with the technology available to us. The second approach is to match the lighting conditions of natural reefs and assume that nature got the formula and balance right and we can't improve upon it. It's a matter of personal choice just like GMO's (genetically modified organisms) or organic foods.
Enjoy the reading & research
