First off never put a plant into a clear container. I see granules of time release so I would guess you are using MG potting soil. Seedlings don't need ferts until the fifth or so set of leaves.

How much sunlight do they get a day? How often do you water? The most common mistake people make is ovewatering. Add that to too much ferts in your soil and you get what you see in your pics.

Now I could be wrong. I hope others chime in with their opinion.