Adding the extra watttage will definately get you more weight and tighter budz, I run 5600 watts on four bushes, never got less than 1.5 poounds of any strain yet, well wait thats a lie I did get only 10.5 zips off a 30 inch frostbite bush, Add the light if you have it, I would put each light a little off to the side of each plant and they will blend in the middle, gets the outside a bit better IMO