Steve,
You want to fill your backyard pond in???
Thinking about it, it's just too frustrating and I don't see getting this pond in any kind of respectable shape without, at least, a dredging. I don't have the bucks for that. Overall, it's just a money pit and a pain in the rear and the biggest factor, the pond is unusable ! I was able to fish maybe 3 times last summer, that's only when the wind would blow the duckweed to one side of the pond. Most of the summer I had 100% coverage of the stuff and if it wouldn't have been DW, it would have been FA.