Here ia a video I made this weekend of my Eco 7 pump in action at 6.5 half feet with 2, 9 inch fine bubble diffusers. My pond is down right now at least 14 to 15 inches though but this same pump does the same job at full pool too.
I did not have a gauge on the pump at this time but if you use 1 psi for ever 2 feet of water then my particular pump must be pusing at least 4 psi as it runs just as good in 8 feet as it is in this video at 6.5 feet. Am I maxing it out? I am sure I am but I only run it a night not 24/7. Ted has been kind enough to send me the pump they were testing and I will set it up on my system also to see if it works as good as my original pump. I am sure these pumps vary in performance and pressure but for 110 bucks that is a chance you are taking. Anyhow just thought I would show my pump in action.
Once again as stated before just because this pump and setup works for me doesn't mean it's the best thing for your particular pond, but it does work for my situation.
RC
http://www.youtube.com/watch?v=cDJ1YOyMrPg&feature=youtu.be
