small ones can be kept extreamly close and surounding the plant covering more area
lumens drop rapidly after the first foot , depending on plant size id figure two closer bulbs would be better
id rather use 4 small bulbs though and completly suround it , ive done test seed plants with 5 13 watt cfls , 4 surounding and one above , they did just as well as the plants eventually grown in the hid flowering room
make sure the temp/color is proper , i buy 3000k for flowering and 6500k for veg when useing cfls , i get em at the dollar store too so thats sweet
peace :Cool: