Are you looking for some buds or just to grow a MJ plant ?
If your looking to actually harvest some bud off that plant
you'll need plenty more where that came from. I would
say you need at least 15,000 lumens of florescent, Metal halide
or High pressure sodium.
Keep in mind 1x150watt HPS will give you that,for a total
of around 16,000 lumens.
100watt HPS= 9500 lumens
70watt HPS = 6300 lumens

Heres a look at florescent:

Standard philips 60watt= 4050 lumens
Standard philips 40watt = 3200 lumens