i have 12 white widow and 4 medusa growing right now in mg potting soil the trick to this soil is to sift it before you use it because there are time releasing nutes that will throw of your ph and will cause your plant to have a nute lock up that causes the leaves to curl up and eventually die off. after your sift the soil you wont have to add nutes till about the second week of vegitation, keep in mind your waters ph balance as well feed your plants water only 3 times a week and plant food pending on the type you use 1 to 2 times a week doing this shall help you in growing large and beautiful plants.
pictures of my garden will soon be up i hope what i have said helps you.
peace and enjoy