I think their site says 6 cubit feet. I think that once the plants are rooted in, watering well from the top should work. You could put in a couple lengths of perforated PVC pipe when you fill the container and fill them from the top when watering- that tip for strawberry pots really works! If you have to water individual pockets or get a hose out, that could be a deal-breaker for balcony gardening.
