Diatom filter with good head?

I uncovered the pond today and it was a bit murky (Three dead fish), so I
decided to get out the Vortex Diatom filter. But I had real trouble getting
the Vortex to stay primed or pump. It kept pissing the contents of the jar
back out into the pond. I greased the seal, changed the filter pad and it
helped. But it still won't work standing up, I had to lay it on it's side to
work. It's probably about 0 head working like this. It just would not pump
at 1' head.

Is there a Diatom filter that's REALLY self priming and has better pumping
ability?