That depends on whether you have a spa with a third pump on not (Legend series spas or above).
If you do, press the Pump 3 key to turn Pump 3 on High speed. A second press will turn Pump 3 off. If Pump 3 is left on, it will automatically shut off 20 minutes after it has been started. The Pump 3 ON triangle icon will appear solid on the display when Pump 3 is running at high speed.
If Pump 3 is not present, then this switch is used only for the On/Off mode. A long press (5 seconds) on Pump 3 key is used to turn the entire system on or off. When power is applied to the unit, it is ON by default.
You would use the Off mode when changing a filter or cleaning a suction cover, or if for some reason you have a door off and are looking inside the spa.
