9 times out of ten leaf curl is from overwatering and in your case, i'd assume it just because you're already giving your just-sprouted seedlings ferts! don't do that...they don't need any for 1st few weeks when using fresh potting soil. drainage is a must as they don't like EVER being soaked and should only be kept moist and slightly dry between the mistings (misting doesn't disturb young roots like regular waterings do). if i were you i'd get a few backups going asap...

lighten up on the love and affection and they should be fine