idk if you have more soil but i would not recommend using the same soil because of contaminates in the soil.. like mold that develops when the moisture in the soil is the perfect environment.. if you must use the same soil bake it in the oven @ 350 for 30+ minutes to kill any unwanteds in there
and how deep did you plant the seeds? plant around 1/3 " deep AFTER they have shown roots when you put in a zip lock bag with a couple paper towels folded around them and dampened... poke a hole in the soil with a pencil and PLACE the seed in there. then put some soil over the seed and let her go. spray the soil surface once a day with a few sprays from a cleaned out windex bottle.
thats basically what i do and it seems to work well and is kind simple
sorry if not to clear im kinda drunk/tired