[Delphinus]

I wonder if the microfauna suffer the same "sheering stress" as they do in centrifugal pumps. You'd think it might be comparable, but then again ... maybe not as bad?

I wonder how the pump will fare in the long run in such an idea. Since we're now not moving an impeller, but a propeller, the weight of the water displaced is different than intended, etc. etc.

But it is a neat idea. An RC plane prop. That never occured to me. I once thought about using an old fan blade, but decided it probably was too much work to figure out how to make it spin under water ... :D