Seedling shrinking after sprouting

Hi, for me it's just a problem of low humidity. Next time if you plant directly in the soil, cover them with a transparent perlicola or even a simple transparent plastic glass which you then remove after the plants have germinated properly, then don't water with a watering can to make them germinate but keep them moist with a spray bottle. However, for me they could easily survive.

Small plants in large pots in heavy medium, in plastic pots = overwatered.( Next time try use small fabric pots and mix medium with perlite). Without dome =maybe low humidity. The healthy ones- too much stretch = put your light closer

no dome for seedlings. Before they sprout it can avoid requiring a watering, but after that is no help unless you are in a very dry climate. need more aeration/drainage properties in that substrate. IF coco should be 33% perlite or similar. If soil/sphagnum peat moss water capacity, needs 50% perlite. I'd recommend using vermiculite #3 as it also adds some silica. Since most of you seedlings are fine, it's probably just the seeds. A good chunk of seeds are less than idea or completely defective. The rate is probably higher than you expect. It's always good not to blame the seed and re-assess your methods, but if 10-20% are runty, that's not too unusual. I plant 200% of need just so i can kill off the weak ones. Still get 1-2 out of 10 that are less than idea in flower, but way better than blindly sending them all to flower, but gotta be willing to throw out some money (seeds you bought) or start breeding your own so that it's never a concern because the cost per seed to breed your own is maybe a 1 penny each.