See if the soil is pre-nuted. If so, I think you should wait about two weeks before you start adding more. (Depends on how heavy the soil is pre-nuted, some types will tell you on the pack). I've seen people kill plants by using too much nutes in a pre-nuted soil.

When it comes to germination, I've been successful with just folding a two-ply chlorine-free papertowel in half, and put the seeds in between. Then soak it in luke water, never let this paper dry out. Store in a dark place (room temperature). I keep the paper on a small plate and fill it with water 1-2 times a day to not let it dry out.

Start checking it after 48 hours, then every 24. Within the first 2-4 days they should all have sprouted. After a week, there is no hope.

Good luck !