An automatic flush toilet tank assembly is provided. The automatic flush toilet tank assembly includes a flotation assembly having a sealing device. The sealing device is adapted for releasably sealing a closure mechanism to prevent water flow through the closure mechanism. The device further includes a blocking mechanism releasably connected to at least a portion of the flotation assembly. The blocking mechanism has a first position for preventing buoyant displacement of the flotation assembly and a second position for allowing buoyant displacement of the flotation assembly. Buoyant displacement of the flotation assembly releases the sealing device and allows water flow through the closure mechanism. The assembly also allows the administration of anti-bacterial products without the need to come into contact with the potable water supply and contains an overflow mechanism in case the water supply cutoff to the toilet tank should fail.
展开▼