Hi there,theres no need to upgrade your bulbs stright away to so high wattage.of coarse it depends from price..i had couple grows before with 7x20w 5600k bulbs and later changed them to 23w 2700k and i still think that using good few smaller wattage bulbs is much better than using 1 big CFL cos when plant gets taller there isnt enaugh light for the bottom leafs when using couple smaller ones you can accually adjust them easily unless you wanna start tieing the plant down.