Nice set up. pH 6.0 is low for growing in soil. It should be between 6.2 and 7.0. Also, your soil may be a little hot for an auto seedling. I use a professional mix soil in my grows to (check out my latest diaries, Purple Lemonade and Gorilla Glue auto) but I amend it heavily coco coir and inoculants. As far as grow bags go, there is no comparison. As long as its good quality they work as advertised, your roots will never circle around the bag, they will divide into millions of micro roots. Peace