Well, I took a few hours to read the thread and follow some links that ended up at the new pfo led light page, which claims a 40% energy cost savings over MH and was linked to a Dana Riddle review.
So, according to Danna, the new PFO hood produces 89% of the PAR of an xm 20k bulb. This is probably the bulb that pfo used to calculate its 'savings'. Given that the 20k xm is not the best of bulbs and produces about 1/2 the PAR of an iwaki 65k, where does that leave us?
Doing the math by quick and dirty guestimation, led lighting is somewhat less efficient than a standard 65k MH bulb.
Still, if you look at the Riddle review (reefs.org advanced Reefkeeping mag) the pfo light looks interesting and a great improvement over what was to be had 2 years ago.
1. the light distribution over the area measured is much better than a MH light.
2. from Danna's tests, it adds no (zip, nada...) heat to the aquarium
3. spectral distribution is pretty good.
4. thats one heck of a controller they have built into the light
The downsides are:
1. As mentioned earlier, one heck of a price tag
2. Following the link from Danna's review to one of the forums it seems that the light, while fine for softies and lower light stonies, is not quite enough for a hardcore sps system
3. the life expectancy of LEDs has yet to be proven and for whites have already been adjusted from 90% @ 1000,000 hours down to 70% @ 50,000 hours. First generation high quality leds fell far short of the adjusted life expectancy (from Phillips Lumileds site) and cheap leds are still crap.
Bottom line (in my mind anyway) is led lighting if finally getting close. Another year or two and a few more competitors and we will see some good options.
Long term, I think led will take over.
Fred
