Excellent response and much appreciated Rainman! Good points all. I do indeed have a significant amount of predator fish in both ponds. I knew that might be a big problem, just wasn't sure how big. I am going to aerate in the future, when funds allow. Complete renovation is not feasible money wise and likely wont be for some time, so that's off the table for the forseeable future.
The Shelbyville example is exactly what I'm after. I want the pond cleared up to a more pristine state. I'm not concerned with other vegitation being eaten as well by any tilapia I stock. I would even consider clearing the predator fish and starting over after the tilapia had done the sort of make over you cited in your example. Lots of things to consider here.
My whole life these ponds have been a dark murky green with to-your-knees muck and I would really love to one day see clear water and a firm bottom. If aeration along with tilapia is potentially a way to do it, I will keep that option viable, even if it means killing off all my current predators. (How it that typically done by the way, if you know?)
