my wife and I are new to the area and just purchased a home. We are in the process of removing the rock and want to lay sod down. We can't seem to get a straight answer from any of the nurseries about if we need to mix in top soil or not. Just need some advice. We have heard, get your soil tested and then mix in propper nutrients?(whatever that means) We have also heard, to mix in about 2-6 inches of top soil with the exsisting soil when tilling? Just so many different opinions!!! This is our first home and just want to make it as simple as possible. Not to mention inexpensive! Thanks!