In theory if you can get a siphon going you are going to pull a lot of water through that pipe. As long as the output end of the pipe is below the input by even a small elevation (remember water seeks its own level) it will keep siphoning. I'd also be curious to know if any one as had success with such a large siphon line as my pond is almost completely a dug out. I get very good flow due to very large water shed but if it ever requires draw down of any significance it will require either pump or siphon.
