I use a light mover with a 48'' vertizontal reflector that looks like half of a space ship, and I can comfortably grow up to 8 fairly large plants.
Alot of people think that more plants equals more yield. Its not the case.
When you crowd your plants together the yield drops considerably.
Better to have ample space between the plants to make sure they get lighting at all angles.
I have grown as many as 21 under the same light,.. and it didnt yield anything near an 8 pack.
Less is more, even with plant count.
I got 39 oz's with 7 plants last time.
I run dwc bubblers and co2.
Check out my thread sometime.
There's a link to my thread below.
Peace, CG