Pond Boss Forums AERATION Systems questions DC aeration pump?

I found a few AC air pumps in the 1/4 hp range that seem to be up to aerating my 140,000-gal pond. Since I'm off-grid, it makes sense to use the DC directly for pumping instead of going through the inverter, simply because of the energy loss from conversion. But I read that DC pumps are made neither well nor big enough for my pond. Am I missing something?

Running the aerator off the batteries means the pump will be off at night, so as not to drain the batteries too low. Having it off at night means more weeks and months before the muck buildup all gets eaten. I want every watt and percentage of efficiency that I can get! Fortunately, our Outback charge controller has some kind of auxiliary relay that takes better advantage of battery capacity than a separate Light-On photoelectric cell.