A toilet system including a bowl and a tank configured to hold water and air and deliver water to the bowl. The tank includes a water inlet and outlet. A valve having a seal pivots between an open position and a closed position where the seal closes the outlet. A lever positioned outside of the tank pivots to push the valve out of the closed position and towards the open position such that the outlet is opened and water flows out of the tank into the bowl. The valve rotates to the open position as water flows from the tank until the weight of the seal causes the valve to pivot back to the closed position. A plunger extends into the tank and applies a force that pushes the valve away from the closed position to the open position.