Whats the dimensions of the tank? 2 will be a lot of light you could raise the lights really high or just use one halide. Will you have co2 and dosing ferts?
Hi, what is the color temperature fo the HQ lamps (Kelvins)? You might as well put them 1 foot, maybe more above the water. Metal halide bulbs are quite powerful. Probably some testing/adjustements to do, and the color temp must be in a range for freshwater plants.48"l, 13"w, 18"t, and the light sits 7" above the water