How Long Will it Take to Drain My 2,800-Gallon Pool?

Flow Rate

• The length of time that it takes to drain the pool depends upon the flow, or discharge rate. The greater the rate, the sooner the pool empties. The flow rate is determined by the size of the discharge hose, and the power of the pump, if any. Using gravity to power the flow rate is going to be slower than having a pump. With a recommended maximum discharge rate of 12 gallons a minute, it will take approximately 3 1/2 to 4 hours.

Municipal Regulation

• Many cities and municipalities have strict regulations concerning swimming pool discharge. Draining directly into the streets or other city property is not allowed. For example, the city of Phoenix, Arizona, can punish violators with "a fine of up to $2,500, imprisonment of up to six months, probation not to exceed three years, or a combination of all three."

Clean-Out Connection

• Chemicals in the pool can negatively affect grass and other plants, so draining the water into the backyard is also not generally recommended. Many homes have an outside clean-out connection to the storm drain and using that is permitted. It is normally located in the yard nearest the bathroom or kitchen or in the backyard near the alley, and may even be in the wall of older homes. The danger in using a clean-out connection is that the water may back up into the home instead of discharging to the sewer.

Right-Size Pump

• Too much water too fast is the usual reason why a clean-out drain backs up. It is better to take more time to drain the pool instead of hurrying it. A rental pump that pushes out 700 gallons an hour gives close to the recommended 12 gallons a minute and provides the combination of safe and fast draining. Place the pump in the middle of the pool, or in the deepest part for maximum effectiveness.