Solid ice cubes made from heavy water on adding to ordinary water at  $3^{0}c$

The density of deuterium oxide is about 10% higher than that of protium oxide at all temperature . So the ice cube of heavy water sink in light water or ordinary water at  $3^{0}c$ and remain solid ice . AS the temperature of ordinary water  $5^{0}c$ is less than the melting point according