You get a pipe tee the same size as the bulkhead and drop in in loose with a hole on the top and one on the side over the open hole. This prevents a vortex from forming. It simply prevents the flow from becoming organized enough.
It doesn't really matter how it sits. It's acting as a baffle to keep the water mixed up.
It doesn't really matter how it sits. It's acting as a baffle to keep the water mixed up.