Hi folks.
I'm always happy when a find a thread becomes useful and I'm hoping this helps out a bit.
Tullio was actually nice enough to email me back with some more info and opinions of his own. rather than paraphrase and get something wrong I'll just paste it here...
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First off there was some minor errors in the data, it was actually 15 watts- 3 five watt LED's and as Mike admitted there was no reflectors for the led's which had a 180 degree radiation pattern which meant a lot of light was actually lost or absorbed. If there had been reflectors the light output would have easily acheived a PAR reading of between 100-180 throughout the aquarium well above the 80 or higher that was believed sufficient at the time. Plus this aquarium was literally the first to demonstrate the future of LED's as we know it today.
Today we have special reflectors and the luminous efficiency of our LED's has gone up significantly. But even back then if you looked at the picture the tank was actually lit up pretty well and the corals where happy. Plus conventional meters do not always accurately plot led output. There is a lot more to understanding and measuring the benefits of LED's than simply adding an array and lighting it up.
There is a thing I like to call usable PAR which essentially means there are very specific wavelengths of light that corals respond to. With Halides and other systems you can show me all the luminous data and PAR data you like it essentially means they need a lot of light just to satisfy the spectral requirements of corals to thrive.
With LED's we can focus specifically on the spectrum we want to essentially color tune to the specific wavelengths of light we are targeting therefor giving the LED an upper hand at usable spectral output versus lumens! If you have the chance to catch one of my talks this year I always demonstrate the fixtures with my spectrometer and you would clearly see that LED's in many ways have come a long way since then. The only draw back is the systems do cost more, same as the first computers when they first came out. As consumer demand grows and production rises costs comes down and so forth.
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'course, I did write him back and ask about the units he's designing and if he's going to be selling directly or through distributors.
I'm a bit torn by the findings since I was leaning toward using what I learned from Mike and trying to place coral at different heights in my tank giving them the light they require. On the flip side, I'm concerned with over-lighting them spectrally and having to frag corals likecrazy
I'm still a firm believer that lighting remains oneof the most complex components of fish keeping esp. b/c we combine animals who tend to live at vastly different depths.