Hmmm.

Berg, I assume your pumps are installed, not used "over-the-side", right?

The real discrepancy is between Berg
Quote Originally Posted by bergermaister View Post
I've timed mine and they take a little over 7 min to fill an 1100 to about 95% capacity.
and Fresh Fish via CenturionCrew
Quote Originally Posted by Fresh Fish via CenturionCrew
Unrestricted Test: 13 GPM or 780 GPH
I'd rather believe berg but like you said, his measurement is a little casual. Plus, I've got to trust Fresh Fish's 780 gph measurement because he was trying his best to do a controlled experiment. So if we assume 780 gph is the best case scenario, the only way to get berg's observation to fit is to take one of your calculations for something "a bit more than 7 minutes" and "a bit less than 95%". But then yeah, there wouldn't be much more loss due to other components. I don't know anything about the brass valve that was used in the test so maybe that was too restrictive.

Then the conclusion would be that the aerator pumps perform about the same as the impeller pumps but are very sensitive to installation, so be careful.

The 25% loss in flow due to head is real and straight off of the spec sheet. Can those pumps produce much suction, if primed? Maybe it's better to mount them higher? But it seems like priming would be impossible.