2 hours ago I would have told you not to waste your money on it.
I bought mine off ebay 2 years ago and never could get it to work right. I took a look at the link you provided and found a tip on how to get it to prime if what you try according to the instructions fail. So I took a chance and lo and behold I finally got it to work right.
I've been outside now ever since vacuuming up the sand and small pebbles that accumulated on the bottom. I can even vacuum the ledges now too! Now that I know how to get it primed right, I am very pleased with this.
Thanks for posting! I never would have gotten it to work otherwise!
I also have a leaf eater which comes in handy if you have a lot of leaves at the bottom, but it's not real good at picking up other things because the holes in the mesh bag let the fine dirt back out into the pond and does not pick up small pebbles. Maybe I need to check into a finer mesh bag for it too.