Cropped above the fifth node, not long after cut off the first and second nodes. Trained horizontally until plants reached ~20" wide and then allowed to grow vertically.
Cheers
Velo (?) shouldn't be necessary...
You could fully water or "wet" the container with at least half a gallon.
I did a test with my 5 gallon fabric pots, after fully watering they started to feel light after four days with no plants. My goal is three days...
Over watering with ProMIx is only...
Fill your cups, Water to run off and plant your seeds. Then leave them alone until the cup starts to feel "light"...
Spritzing is useless, the seed will grow a tap root into whatever water is in the bottom of the cup. When needed, a small amount of water around the edges will encourage side...
Little late now but I believe your issue is watering.
I fully water my solo cups of ProMix HP with .7g/4L of MC the day before planting the germinated seed.
BTW > I germinate in distilled water with a spritz of hydrogen peroxide. No fooling with towels ;)
Each seed gets their own shot...