How to Get Water Out of the Return Lines of an Inground Swimming Pool

Unscrew the plastic caps from the ends of the return lines. These are located around the inside wall of the pool and should be easily removable by hand. Handle them carefully to avoid damage.

Turn off the pump and entire filter system.

Locate the drain plug near the bottom of the pump. Unscrew the drain plug with a flat-head screwdriver.

Attach a threaded attachment on the hose of the air compressor.

Plug compressor into an electrical socket and set it beside the pool pump. Screw the attachment into the drain plug to get a tight seal, then turn on the air compressor.

Walk to the pool and look for bubbles coming out of the return lines, as well as the skimmer, if applicable. In most cases, the air will go through one line at a time.

Watch the force of the air bubbles. Once the bubbles come out strongly and it appears to be only air with no water, push a rubber plug into the pipe to seal it shut.

Repeat the process until all return lines are plugged. If the pool has a skimmer, screw a skimmer gizmo into the return port, typically located at the bottom of the skimmer tank. The threaded end of the gizmo should screw in snugly with the skimmer port.

Double-check to ensure all lines are tightly sealed, then turn off the air compressor.