I got 1 1/2 inches of rain in the pond gauge last night, and it was practically emptied except for the mossy gunk in the very bottom. There was at most 1/4 inch of that, so I got 1 1/4 inches. Pretty great.
The result so far is ugly, but I'm moving the aeration pump to another location. The boat is too heavy to deal with when it is full of water, however that happens, and having the pump attached to the end of it temporarily has been going on for 3 Summers. We still need to oxygenate the water for a couple of months more and this is another good, temporary, solution.