Hey bud

You can grow with flourescents BUT what you really need to veg your babies is the cool white ones. Im not 100% positive but i think 2700K is in the wrong spectrum, I could be wrong though. If you got room for the 48 in flouros then use those, just make sure they dont get too hot and burn your babies. Save those 2700K bulbs for flowering. Id suggest you get another 2 40 watt ballasts for 7 plants and that is still cuttin it close. So heres what you should do:

1. Get 2 more 48 in flouro ballasts
2. Get cool white bulbs

feel free to ask questions!