After germination

To safely remove a shell, you need some tweezers or small enough fingers you can be confident you are only holding 1/2 the shell. The tweezers hold it steady. You don't want it moving from a fixed position to ensure all stress is placed on the seed shell and not the cotys or stem. Use a toothpick or another set of tiny tweezers (the type in a swiss army knife work fine) and gently pry open the shell further. Once looser, it should fall off. If there is a membrane holding the cotyledons together, gently slide it off the end - don't try to rip or tear it. It's easier just to poke in behind it (between cotyledons) and slide it off. If it sprouts with a shell, it's unlikely to rid itself of the shell. Plus, the sooner you get light hitting those cotyledons, the sooner it can start developing properly. If you get too many shell-heads, plant seed deeper or tamp down a bit more. It's a trade-off of faster sprouts vs fewer shellheads. I usually get a couple out of 16-20 plants. I try to avoid most but want sprouts as fast and consistently as possible while doing so. You do it a few times and it's not so scary. If it's fused to the shell or some other oddity, then it wasn't going to survive anyway. It should be easy to remove a shell without causing any damage, if you do as instructed above. Tip - you need fluffier substrate. that looks tohave almost zero drainage amendments. Seedlings and mature plants grow better with a better gas:water mixture in the soil. With high capacity substrates, you want 50% perlite or similar amendments. With something like coco that holds less water per volume you only need about 33% perlite or similar. that stuff looks like dense mud. There are drainholes in that, correct? Soldering irons make clean holes.