Here's the whole thing:

Most of the lights are off so I could get the picture.
There's a few banana seedlings in there, just so when you go "what's that", that's what.
The pyramid shapes on the top house 1 75 watt hallide bulb & 1 150 watt flourescent. Under each back shelf are 2 40 watt flourescent bulbs, the common "shop light" kind, and under each side shelf are 2 22 watt (each) compact flourescent bulbs. With all the lights on the thing pulls 500+ watts, and lights the whole room.
The tube looking thing on the middle top is a chimney above one of the cooling fans (activated by the thermostat near the bottom of the terrarium) which aids in cooling the whole thing by convection. As the warm air rises up the 'chimney' it pulls in cool air through slots in the bottom. (look at the bottom left- see the slot cut in the plexi? That's a cold air intake.)

The back & sides are 1/4" plywood, with reflective mylar sheet spary-glued on to create mirrors directing the light back toward the plants. The underside of the top just happens to be a highly polished side of plate aluminum I found at the recycler's It's almost "mirror" quality.

Humidity is adjusted with a humidistat (near the bottom of the terrarium as well) and a home-brew ultrasonic humidifier I tore apart & remade to my spec's. It blows mist down from above, and the entire device is hidden behind the chimney. When set at 65%, I go through about a pint of water every 2 days.

The shelves are 1/8" aluminum plate I picked up at the local metal recycling place (it's sold as 'scrap' there & I get it by the pound) with 1/2"x1" wooden sides bolted on. Cracks are sealed with 50 year silicon calking, making watertight trays within which the water can be about 3/4" deep if I wish.

The lights are controlled by an appliance timer ($5 at hardware stores) & is "on" 18 hours, then "off" for 6. Thus the plants "see" an 18 hour day with a 6 hour night. The heat & humidity controlls are "on" all the time, however rarely turn on during the night cycle.

Here's the bottom shelf, closer:

The bottom right side, showing the thermal & humidity controlls:

And one of the small side shelves: