1 will do for a few days, untill the plant gets bigger. If you wanna grow it and flower it (and actually get bud from it) then you will need more than just 1 CFL. I'd say about 6-7 for a really good harvest. Make sure they are all the highest wattage you can get. And you really do need to get a small fan, just to strengthern the stems, you dont want it to fall over and die while your budding it do you?

If you can get a good fan, get a computer fan or and Sony Playstation 2 fan and wire it up to a 9 volt battery.

Good luck.