So, generally, my setup operates in two integrated parts, in theory:
Part I, Ebb and Flow: Water runs from fish tank via 500 GPH water pump => 2 biofilter grow beds => through bell siphon (CTAHR-style) => sump => overflow returns to fish tank.
Part II: Continuous Flow: Water runs from sump via 250 GPH water pump => 2 white floating rafts grow beds => overflow from grow beds returns to sump => overflow from sump returns to fish tank. Note: the fish tank is not shown. It's located in the slightly sunken basement, behind the brown laths of the house.
Goodness, I really hope this works.