I don’t mean to butt in here but I’m running four in a 90x90 area and it’s overkill. I could easily stretch these out to fill a 120x120cm area easily. One per plant will give you great results no matter the size of the area. Well unless you are trying to put them all in a 60x60. Also you will be pulling only 220watts at the wall compared to 600w. Needless to say the heat will be much less as well.
I'll be running five of them in a 4ftx4ft when my season starts back up.
Now to decide what I'm going to grow this year.