I have mine on the bottom under direct lighting of a 250w 14k MH I have mine proped up with rocks...PVC can work as well, I have never got a feeding response from mine but have it in mod/high flow and a pair of B&W clowns hosting in it.....Mine is 12" across and about 6'' deep almost a perfect bowl.....Here is a pic of it...
The angle is hard to tell but it goes from one side of the tank to about the middle....The tank is 24" wide.