Miracle-Gro is not ment for weed neither is there perlite why? Bc they infuse both with food so everytime you water you feed this can burn your seedlings, the geniuses at Miracle-Gro allso add sodium ie salt, I use on houseplants and have found trash and fruit Flys or gnats, I recommend Fox Farms ocean forest, or
happy frog witch is a bit hotter add 20% chunck perlite for aeration or Pro Mix same drill. Use nursery pot's and clay pebbles for good drainage, you will see a major difference.