Jeff, I don't know how either one would work but there is more information on types of pond vacs,etc in the thread linked below.
I would like to know just how effective the one made from a swimming pool filter pump is. The link to it is in the other thread.
"Horton"

Here is a link that might be useful: Pond vacs, etc,.

horton, i tried a shop vac this spring and it kind of worked, but it would fill up fast and was a pain. i've seen a sand filter and regular filter type with a small pump on craigslist. i was wondering if anyone had any luck with either kind.
i think the bigger sand type would suck up everything including rocks and fish. the link you gave me looked interesting, something like i was looking to build.
thx jeff

Jeff,
We had a pool which we converted to our present pond. Having cleaned the pool more times than I care to count I can tell you that a sand filter, aka pool filter, will clog quicker than you can whistle Yankee Doodle! Plus the fact that it takes a tremendous amount of water to backwash the filter to breakup and remove the "stuff" from the sand. Check out the systems Horton has suggested.
---David