Pond is approx 1 surface acre, very shallow sides, except for dam, and in front of dam maybe 12 feet deep. Power is available. Have pretty much ruled out windmill and solar. could use single or multiple diffusers. There is a budget, but not unreasonable. Have two recirc pumps already, one for fountains, one for end to end recirc. General shape of pond is traingle. I might be able to put it off until next Spring, but if not I better get on it.