It looks like the only leaves that are curling are the cotyledons or the first leaves that appear after germination. Once the plant has developed true leaves, the cotyledons serve no further purpose and die off. Usually they just yellow and drop off but they could curl up prior to that as well.

If it IS only the cotyledons that are curling, no cause to worry :-)

Thanks

Curly cotyledon syndrome!

every plant in the pic is leaning toward the light.. and looks like its etoliating ... your lights might not be strong enough... of the plants not close enough ...

what gal said about the curling

at a min.. turn the trays every day or so ... until they grow straight up ...

just as an aside.. i never had great luck with the peat pellets ... hope you do better than i did ...

ken