Will airstones at the bottom of a flooded container work with Grow-Cubes?

Airstones will not provide enough oxygen in a stagnant system. You may still risk root rot with the plant's roots sitting in water. Also the plant's roots get lazy when they are being fed constantly. Grow-Cubes already have a high air capacity, but still hold plenty of moisture (much more than expanded clay). The best use of Grow-Cubesis on an ebb and flood tray (flooded 1-4 times per day) or by top feeding. You can place the airstones in your stock tank for added oxygen.