Some valid pros & cons already mentioned re going with fewer, large multi chip LEDs. Although my build also uses 10 watters, I've been following the huge thread on RC about the 100 watt emitters with interest. There's still a lot of wiring involved in doing up a 10 watt array for larger tanks and this could be averted by using 3 or 4 of the 100 watters, similar to a halide pendant set up. You need to use optics & mount them up high. The con, already mentioned is the price, although when you consider some folks pay upwards of $60 for a Metal Halide bulb,.... that needs changing at 6 months or so....
The group buy linked to in this thread involves a custom colour multi chip designed specifically for reef tanks. If you're looking for single colour 100 watt multi chips, they can be had for as little as $30 these days on fleabay. I don't think the price they want for these fancy emitters is over the top considering they are a custom design with the ratio of colours packed on to the single chip deemed ideal for reef tanks. The chip also has the capability of being driven using 5 or 6 channels to mix/tune the colours to your liking.
I have a post on Aquttro's LED supplementation thread relating similar info & including the photo below, of Mr. Wilson's 100 watt pendants. Here's the photo & check the link to Aquattro thread, post #75. If you want to know more about 100 watt emitter's & their performance, Mr. Wilson is a good source, he runs a shop in the Toronto area.
http://www.canreef.com/vbulletin/sho...911#post757911
Tank in Mr. Wilson's shop lit by 100 watt LED pendants.
