I have a 48 inch dual t5 light fixture with a third option for led moon lighting.
The lighting seen in this picture is with the blue t5's only. I usually don't run the whites because its too hot and I don't need them on for anything.
The canopy is hallow and holds two pieces of wood that hold the light fixture about 8-10 inches from the surface. This makes it easy for maintenance and allows for air to pass between the lights and the surface.
I have also removed the glass from the DT which has kept temp down and the lighting poifect IMO
As for the rock layout, we went for many openings and caves for everyone to swim/crawl in and out of. Everything is set up with the idea of two vertical rocks holding one horizontal. I wish I could show you with one of those mini cameras but the system has worked well with flow and a safe system for those who prefer to travel away from the open waters
Also, I find it very important (in the past and now) to not place the rocks against the back of the DT. I know this works for those of us who want to see everyone out in the front of the DT, but I don't like dead areas in my LR. Especially when I have had to pull a dead fish out of the tank. Ahh the things we learn lol
More pics to come