I'm no artist, but I will try to explain some more.

I bet if you had the pump you would understand. The 802 Aquaclears are big and kinda rectangle. There should be 2 of those U shaped elbow sets. One for the first pump and one for the second. The output of the pump goes into that U and then down into the compartment. The pump rests against the walls of the compartment and hangs on the U.

I never saw the other pipes that were wrapped in floss, but I was told to get some PVC and attach it to the input of the pump and cut slits in it and then wrap it with floss. The pump will draw water from these inside the compartment.