Yellowing?HELP ASAP

I'm with dream too...

@DreamIT is correct on those first leaves(if you can call them leaves), they are what emerges from the seed to get it going. They always dry up and fall off eventually. But your plants are looking like they are having other problems as well. I seen the one plant really moving in your video, looks like you may have a fan blowing directly on them, make sure this is not the case if it is. Your flan should be blowing just above your girls, blowing away the hot air between them and your light. Also check your ph meter calibration and make sure you are feeding water in the PH 6.0ish range, no higher then 6.5 or lower then 5.5. I try to hit 6 so there is play either way. Also check your runoff and see if you have a buildup in the soil. If you put in say 400ppm water and the runoff is 1500ppm you need to flush them. Hope this helps. Cheers 💨

@DreamIT has the answer for ya. Happy growing🤙🌱🌱

The cotyledons are designed to get the plant started at the very beginning of its life, and once it's producing more leaves, these aren't really needed anymore and will often yellow and eventually fall off. If these are your only yellow seedling leaves, your plants are perfectly healthy.