i'm currently running 400w of PC on my 75, but since i'm restarting my tank i'm debating on whether or not i should switch to MH. i want to eventually, just trying to see how much money/work it will take. my current canopy is probably around 7-8 inches from the surface of the water. would i be able to run a MH setup with that much space or would i have to add on to my canopy in order to make it taller? if so how much taller?