depends on what medium you started them in. If you planted them in pre-ferted soil (Miracle Grow or the like) I'd wait. If you started in a lighter mix (Jiffy Mix, vermiculite, perlite, coco, peat)
Very lightly fert now. I've seen so many seeding get killed with kindness early on. Be patient with nutes and watering to start with.
Good luck
Got a bunch of 2 week old's coming in nice.
I was wondering when do you guys normally start adding diluted ferts to them?