Close off all skimmer ports except the port that is closest to the pump and filter. The skimmer closest to the pump will be the skimmer that you use as an exit for the vacuumed debris. Use a number 10 rubber plug to block the skimmer suction valve, or slide the vacuum port door closed on the skimmers if your pool is equipped with skimmer doors.
Set the valve setting on your pool pump to "skimmers only." This will help direct the flow of the vacuum and increase the pressure for better suction. If you do not have a skimmer setting on your pump, then leave the filter on as normal.
Attach the vacuum head to the telescoping vacuum pole. Attach one end of the vacuum hose to the other opening on the top of the vacuum head. Slowly lower the vacuum head and pole into the pool water.
Lower the entire vacuum hose slowly into the pool, starting with the other open end. Lower the hose into the water 6 inches at a time to decrease the amount of air inside the hose. Completely submerge the hose to fill the entire hose with water. This increases the pressure in the hose and allows the vacuum to suck debris up more efficiently.
Slide the free end of the pool vacuum hose inside the remaining open skimmer basket. Attach the skimmer head to the end of the vacuum hose. Lower the skimmer head inside the basket, creating a tight fit over the top of the skimmer basket. The vacuum will spit out the dirt and debris through this skimmer basket.