400w Metal Halide for first month of flowering?

[growbe]

Will a 600 watt cover a 3x6 area? Or will i need another light if i get a light rail. Im savin up to get a digi ballast and a decent hood... I like the sunsystem hoods..

P.S. back to the MH thing, Could the absence of the red spectrum delay the onset of flowering?

Never used a 600 on a rail in that size of a room, but I'm growing in a 6x2.25 room right now with 670 watts with a rail and it's working great.