Your Setup is quite nice. 900 W ist alot for Blasting on the Babies. Normally 200-300 will do the whished effect, dont quite understand why they are stretching like this. Its normally a sign for lack of light.Your datas looking very nice from Humidity, temp and Ph... is a mystic thing.I would recommend digging them deeper into another pot... but you want to do dwc with them?....... I would add a soft airflow to them so the stems are moving and getting fatter. maybe that is the missing piece in the Puzzle, watch your video now maybe i see more. then i write in the comments