Just wanted to see how high people have their lights? Leds, metal halides, or t5s? If you can include the depth of your tank and what you have mainly sps, LPs, or softies.
Over my 75, 2*250MH + 4*54 T5, older Current fixture with legs, would guess 3" from the rim of the tank.
65 2*250 MH + 2*96 PC, old Hamilton full fixture, sitting on some old CD rack shelves, about 3" --- picture below.
40 6*39 T5, TEK fixture with legs, would guess about 6" off the rim.
Don't have any temp issues with any of the tanks -- though in the A/C never gets above 75*.