Front view shows grow bed over fish tank arrangement, which allows some place for the fish to hide in the back. Note the aeration bar (outflow from the grow bed).

Just visible underneath the grow bed is the end of the outflow piping from the bell siphon, which many advise adds some back-pressure.

The pump will sit on the bottom of the fish tank at the back, with a standard 3/4 in garden hose connected to the inflow piping above, on top of the grow bed.

The poly tanks are quite sturdy, but I expect to make some framing at the ends of the grow bed so it doesn't get bumped off the fish tank.