you need to go to www.overgrow.com and read the grow guides....asking that question i assume you dont have the first clue about growing ? thats ok dude im not raggin by no means we all start out somewhere....this is a good place ...( read the forums and see what other ppl ask and the answers they were giving....another is to follow the grow journals ppl are doing....im doing one right now myself....but start at over grow and read here...gl to ya