Good reference Cecil. I think the thing about diffusers is that thay don't circulate aerated water that well. There may be a great source of aerated water around the diffuser, but in the slack water areas, not so good.

I may have to look into a spray system. The pond I have has one and worked by taking sand point wells and pumping groundwater into a spray thus filling the pond. When the pond was full it would spill and flow down stream. They raised trout here all year round. That system hasn't been activated for ten years or more (before my time). It's pricy to run a couple of two horse pump motors around the clock. I've not tried to activitate the system and suspect it would cost a bundle to get running again.

I've considered surface mounted pumps and spraying the pond. Plugging seems to be a major problem with this approach. Any comments for you sprinkler folks?