spend $12-15 and get Fox Farm Ocean Forrest. many will say this is the best soil you can get for growing cannabis in. I'm using it right now and have absolutely no complaints.

stay away from miracle grow (as well as all other soils that contain time released nutrients)...if you use these, your baby seedlings face a big risk of getting nute burn and dying because they are too young and small to take in nutes.

just make sure your soil has perlite in it to some degree. a good rule of thumb is 4 parts soil to one part perlite. i dont add any extra perlite to my FF Ocean Forrest though.

good luck and keep us posted.