If your talking about the HPS flood lights, like from here http://www.e-conolight.com/Product/EFamily.asp then You can grow 2 of them I would think. The problem about the small HPS lights is that they dont put out enough lumens, so thats why you cant grow as many as you would in a 400W setup. Im buying two 150W floods from there and growing about 4 plants with them, but I have a small area too.