seeds Update on naga seedlings..

Well, after talking to a friends mom who has a plant company, she said to separate the naga seedlings and they should do fine. So, instead of killing 2/3 or my new little guys, I decided to just separate them and put them in their own containers. Not a single one wilted, and in just 2 days they are all growing their first few true leafs. I guess they were not too happy about their neighbors.
Since they are in seed starting mix, should they be givin fertilizer or some sort of plant food now that their growing true leafs? If so, what kind, and how should it be feed to them?

Thanks

I would wait a bit before giving them fertilizer.