They look like they are flowering automatically because in some of your photos I can see pre-flower. In this case, you can leave the light 18-6 since autos do not require you to change light schedule, if you wanted you could grow them 24-0 for the entire grow and they would still flower. Your plants look healthy enough, but they look stunted to me, in your diary they are still small seedlings at 3 weeks, when they should be hitting veg growth and jumping up to 5 or 6 nodes and more at that point. What lighting have you had them under and how far away?