All of my AK48 seeds germinated in jiffy cubes (zero nutes) within 24hrs, started growing like they're on steroids, true leaves have appeared and now three days later they are almost 4' tall. I'm worried they are stretching out too much. Currently they are on the window sill, I guess this doesn't provide enough light and hence the stretching. I have a 400W HPS but no other lights. Would it harm them to stay (stretching) on the window sill for a few more days, or should I move them under the HPS already? Will they recuperate from stretching?
If you have room in the pot them put extra soil around the stem and bury some of it, or use I plant tie or something and tie them to something for support. I think the HPS will make them stretch just as much so I'd just go with that. CFL's are great for veg, they are cheap and you can put them right over the seedlings to avoid stretch
Bingo. They could stretch to the point that the stem is so thin it collapses and the sprout dies. Re-bury them to within an inch of the first leaves.