A multi-function tank tool including a body, an internal passageway, an upper end and a lower end. The lower end is configured to connect a hose so that a fluid travels in the internal passageway. The upper end includes at least one opening communicating with an interior of the tank. A first hose can be connected to a lower end of the body. The tank may have oil, vapor and an oil/vapor interface. The tank tool can perform at least one of the following: grounding an interior of the tank using at least the tank tool and the first hose; agitating one or more fluids traveling through the internal passageway to mix the one or more fluids traveling through the internal passageway; directing a hot oil adjacent the oil/vapor interface using at least the tank tool and the first hose; and, attaching the tool to a floating tank roof.