Topsoil is often too dense with too much clay for MJ. Also, the bags are rarely sterilized so pathogens and insects are common. ProMix is fantastic, and much better to use than topsoil. It is also less expensive than Fox Farm and you can get much larger bags.
Also, adding %10 perlite, %10 worm castings, %10 washed builders/all purpose sand and Espoma Plant-Tone to the mix will give you an amazing grow. These materials are pretty cheap and easy to find.
Mine are growing like weeds in the stuff and flushing is easier due to the increased drainage. It's more work to mix the soil but that preparation will give you a much easier, faster and better grow. The Plant-Tone is not necessary but I love the stuff and its cheap.
When using soil, preparation is everything. Spend a little more now and have far fewer headaches later on.