The Remora hob is what I use on both of my 28 gallon JBJ's. It flows in to the center sump chamber and the pump fits in the chamber next to it. The smallest pump that I could find is an 800 Rio. I have had no issues.
I am baby sitting a friends 28 gal nano
Cube. It had no skimmer & needed badly.
I'm not a Baller & cannot afford 2 buy my friend skimmer.
So I made a ghetto skimmer that is working IMO as good as any nano skimmer I could have bought.