Rebuilding hardware set up

[jassz]

The item at the back of this picture is attached to the line coming out of the sump pump. So that is how the water is returning to the tank, correct? If I disconnect power, does water flow back the other way?

The item at the front of this picture (the U shaped thing) goes back to the Fluval filter. Is this what you mean needs to be adjusted higher so less water drains back?

I can't see how it can be the first item (at the back of the tank) as it is submerged into the tank several feet.