I use the 100w bulbs that use 23w. I get them at lowes for about $5.00 each. I use 6500k for veg and I would use 2700k for flower. I would use 6 for 2 -4 plants. 2 on top and the rest around the sides. I use 8 for 8 plants myself. Check out the cfl club under indoor growing to get some more ideas. Flat off white paint reflects almost as well as mylar and its cheap. Good luck. Peace Out!