I recently was given the challenge of setting up a reef system with custom recessed lighting 5 1/2' away from the tank. Using off the shelf and custom components we built three 250 watt fixtures. LEDs are CREE XPG2 and XPGE2, Count per each fixture is 27 CW, 6 NW, 21 RB and 24 B.
Woohoo! Using 16° optics we we're able to get very focused lighting
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Here's a view of the tank and lighting. Lights are recessed into the bottom side of a balcony 5' above and set back about a foot from the front. Distance to the front top edge is 5 1/2'. Ceiling above the tank is 18' and keeping the area completly open was a requirement so hanging pendants was not an option.
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Here's PAR from the front:
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Here's PAR looking down from the top:
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Another challenge is the system gets about 1 hour of sunlight each day. Combined PAR is over 900 at the top of the aquascaping so LED cannot be on during that time. It's also been interesting to see what corals do not like getting any sunlight so there's a bit of hit and miss we don't usually have.
Here's a video:
https://youtu.be/Oaf3pCvBzX0