Hi Tim I have one question.
Are you using natural light to light your reef?
I didn't notice any lights hanging in the video you posted in top down thread.
Hey, the system does get sunlight filtered through bronze tinted windows mid morning. Depending on time of year it varies from about half an hour in the winter to 2 hours in the summer. PAR from sunlight is about 500 at the surface. But I designed and built custom ~250 watt LED fixtures using 16° optics and mounted them in the ceiling under the balcony. PAR from the LEDs at the surface is roughly ~450 PAR @ ~5'. (Care has to be taken the lights aren't turned on when the tank is getting sunlight.) You can see the reflection from the fixtures in the surface of the tank and I've got a video showing their location on my youtube channel.