It's confusing I know. The pump pulls water into the skimmer. Foam is made and goes to the top cup. That red pipe is for the water to flow out of. The water in your sump is from the overflow and it goes through the chambers to the return pump which returns water to the aquarium.ok thanks! are there any pipes that should go into the chamber the skimmer's in? The chamber you all keep recommending for me to put the skimmer in doesnt have any pipes that lead into the tank.
So the sump has a cycle of where the water goes to first and last.



