Hi Audiocide,
Sativas are my goal also,what I have found out is that halogen bulbs are worst, than anything else in fact they are only good at burning plants.To save on electricity use flourescents ,it may take a bit longer,but you can grow monster buds as long as you use enough of them.I use 4 foot tubes about 1-1/4 inches thick,they come in two basic flavors;cool blue and warm white use both colors together throughout your grow.The key is to keep the tubes within 2 inches of the plant tops,also use a few CFL below to add light where the top bulbs canĀ“t reach,caution; CFL bulbs can burn leaves,keep them 3 or 4 " away from the plants.Happy growing.P.S. What country are you in?