Although many use pure Fox Farm Ocean and Forest (FFOF) for seedlings and report excellent results, I recommend that you mix FFOF 75/25 or 50/50 with Fox Farm's Light Warrior (FFLW) for delicate seeds and seedlings. I used to use straight FFOF until I found that a mixture of FFOF and FFLW provides a better grow (in terms of 100% organic grows at least) overall.
Good luck!