when I first started messing around with aeration I hooked up a 12 tire pump, one of the real small ones and could easily run a small section of hose that I perforated with a hand held wire brush, for 3 hours on one deep cycle battery. I think it would run longer but the motor would get hot so I would shut it off. The pump I was using I believe was a diaphragm pump that was very cheaply made and didn't have sealed bearings of any kind. I cant remember what the actual amp draw of the motor while running was. I just thought I would pass my experience along. I have no idea if it was enough air flow for one 9" diffuser but I am thinking that it would have been since mine was a crude design with varying size holes to produce the bubbles

A little snow, Please!