Sorry, yeah I'm all over the place with the ideas on this thread.

Right, I was thinking of adding a fish catching basin+settlement tank,
open and pond-side, rather than a sealed tank by the pump. That would
save having to carry critters out of the basement, and would give me a
chance to add a bottom drain shutoff valve outside which I kind of
wish I had, rather than just the pump area ones. Of course the digging
4-6' down is a drag, but I'm focusing on design rather than my back at
the moment.

Basically, I don't want to end up pulling so much with the pump that
there's no settlement occurring. It seems to me like a good approach
would be to have a "fish catching basin" that feeds in a fish-proof
way to a settlement tank/vortex rather than combining the two into
one. Or doesn't it much matter?

Dave