as for the drooping of your leaves. move the lights closer to the plant and even ad more light to promote the leaf perking up. and dont water but every couple of days. for the flowering of the plants definatly wait for the leaves to get back up before you change to the 12/12 lights. but you can start to flower whenever you want but just know that the smaller your plants are when you start flowering the less you will yield when your plants are fully mature.