Hey Moe.. I'd agree with MrNiceSmoke on this one - Your medium looks like it's retaining too much moisture which will lead to the suffocation of your plants. It appears to have a lot of clay in it. Since they are still relatively young seedlings, you have time to re-transplant. If you work carefully you may to able to do this with out harming their root structure in any way - but be sure to get all the medium out and replace it with a fibrous medium perhaps peat/coco based such that drainage is optimal. The medium should always be allowed to dry out following a thorough watering, usually within 18-24 hrs.