Droopy and dark green top leaves

Hey guys. I'm growing two plants. They´re bagseed. One of them is doing pretty well, but this one here got all droopy, mainly on the newer top leaves, and their color is like a dark greyish-green. They're also getting that claw shape. Ph is fine, I'm currently using diluded worm compost and bone meal as fertilizers. 4 weeks from seed, natural light through a window with 6 hours of direct sunlight. What could be causing this?
Thanx in advance

Over watering can do this. Do you let them dry out a little before watering again ? More info on how you are growing them helps a lot. Lights, space, fans ect.

just wondering is that summer or winter light? its going ok , prob needs more light.

that soil looks like it can use some aeration, like pumice or perlite....

Thanks for the fast replies.
It's summer here, my window gets only 5 hours of direct, from 3 to 8PM. I know more is needed, but the other plant is doing great and gets exactly the same care as this one. Soil has perlite on it and it's well aired, draining ok when watered. I don't overwater, usually check if the surface has dried and that´s like every 2 or 3 days.
No fans, airflow and a little wind from a slightly opened window. I don't know if this helps but they`re behind a white curtain, next to a big window. I think the reflection of the sun on the white fabric is working. I don't know if this helps, but the other plant has developed a thicker stem (not because of more wind, that's for sure).
Thanks again!!

Help anyone else?

Too much nitrogen maybe?

What size is the pot? What's your watering regime? What kind of soil are you using? Did you amend the soil with anything?

5-6 hours of light per day is not going to be sufficient; you should buy a light.