I am not familiar with that particular soil but you already know that blueberries thrive in acid soil. When I put my first blueberry plants in (20-25 gal. pots), the grower said pot/plant them in pure peat moss. He specifically said, other than a handful of Osmacote mixed in well, don't add anything else to the "soil", just 100% peat. That's what I did and the plants grew well. Just be sure the barrel(s) is well draining.
