Complex Plumbing Question

[Ehunforfun]

I’m designing something for my own uses, and I’m curious if this is possible...

Can a line be plumbed from either the display, or sump with an open port for feeding, and then pumped back into the display? Basically a closed loop system with an open port for dropping some food into...

I’m thinking like a Venturi valve could work? What I know about plumbing tells me this is impossible but I’m wondering if anyone knows of a method that might work?

 

[hdsoftail1065]

I'm not a plumbing expert but following to see the final outcome.

 

[Muttley000]

I've thought about this too. Like a t on the inside the sump side of the intake of my return pump (external flooded suction) so it could broadcast food I dripped in to all 5 tanks it returns to. I can't comprehend a way to make it work without sucking air

 

[Ehunforfun]

I think I figured it out...basically immediately after posting.