A water-treating device having a water jar, a magnetic agitator, an additive container having a bottom plate and a sleeve attached to the bottom plate, and an agitator driver that rotates the magnetic driver. The sleeve of the additive container has an outer wall, an inner wall, and mineral particles filled between the inner wall and the outer wall. The magnetic agitator has a base and a Y-shaped fin that protrudes upward from the base. The magnetic agitator has a magnetic bar between the fin and the base. The base has a shape of a disc having an upper surface and a lower surface, wherein the lower surface is convex. A metal plate is attached to the lower surface. The bottom plate also has a metal plate that contacts the metal plate of the base.