I have been trying to find out if there is a difference, and if so, what is the difference between a metal halide aquarium light and a metal halide grow light? Are the spectrums different? Can a grow light of the same wattage let's say a 400 for example be used in place of a aquarium light? The reason I am asking? Grow light fixtures are less expensive then aquarium fixture? And since I am looking for a pendant type thought I might go that route. Thank you for any assistance. :look: