Stem and main branch thickness

U are flipping too early. With too many low nodes sapping up energy. You need to define your shape. And stem thickness really is all about energy and how you direct it. If there's too many points that draw in energy you get thin leggy plants. Also the plant is FAR from scrog ready. You need 70-75% of your net covered before you flip. Nodes needs to be weaved and through and attached to the net then flip and train through. Also your Burple isn't helping. They really are old leds. Not great. You need strong blues. But, here's a few thing you can do. Your plants look leggy. Move your light closer or increase your ppfd. Also silica will help this and strong air makes for stronger stems that leads to helping build a better thickness of ur stems..