Hey boss, you're falling behind actually. By the amount of stretching I can see, you should lower your light quite a bit. Just make sure it's not to hot for your hand and it's fine for your plant. These autos have a short grow cycle. There's no need for an 18hr schedule. At the most I'd give 4 hrs of dark the first couple weeks for root growth but then it's 24 hrs a day. May want to adjust a little. Also my two BD are THIRSTY as hell. They drink almost 2x what the Northern Light pair drink.
Hope I helped ya bud. All just pointers I've come across. Best of luck.