The ocean accounts for only 0.02 percent of the Earth's total mass. It has long been speculated that the Earth's interior may host a significant amount of water. Previous experimental and theoretical estimates of the water content in the Earth’s mantle span a wide range, from 1 ocean mass to 7 ocean masses. Here, we investigate the water solubility in the most dominant silicate phase in Earth, MgSiO₃ bridgmanite. Specifically, we perform the large-scale two-phase molecular dynamics simulations of silicate and supercritical hydrous fluid at conditions relevant to the deep Earth interior, which are made possible by the machine learning potential of ab initio quality. The trajectories of hydrogen in these simulations directly inform the water solubility. In this talk, I will present our recent findings on the water solubility of bridgmanite and discuss the implications for the water storage of Earth.