Skunk No.1 Auto First Grow

Can't figure out some of the issues I'm seeing. Tried adjusting humidity (40-60% now) and not overwatering. Temps 19 night time, 26 day time. Added a tiny 1ml/litre feed of plant magic old timer grow yesterday 600umol/m2/sec PPFD of light from Metal Halide bulb They're slightly yellow and leaves curled down and it's been 3 weeks since sprouting and they're still super slow growing. They're tiny. ‐------------------ Edit. Potted up and the roots were touching the bottom and spiralled around the base. Still learning as this is my first full grow indoors. I've definitely messed up a bit but live and