Bruce :

How does your system (or does it) put O2 into the new water coming out of the system. I understand what happens when it hits the pond and how it works wrt that. Is there air added to the pumped/sprayed water?

Here is a excellent fact sheet on aeration (commercial).

Pond Aeration

http://srac.tamu.edu/tmppdfs/13098998-SRAC3700.pdf