NOVELTY - A water storage tank of soft water treatment in-built solar energy water heater, comprises a water tank, a water inlet pipe, and a water outlet pipe; where the water tank is set with a vertical insulation isolating plate for dividing the water tank into two independent spaces; the two independent spaces are respectively a soft water tank and a main water tank; the soft water tank is set with an ion exchange resin; the soft water tank is connected with the main water tank by a pipeline; and the water outlet end of the soft water tank is connected with the lower end of the soft water tank.    USE - The water storage tank of soft water treatment in-built solar energy water heater is useful for industrial and commercial applications.    ADVANTAGE - The water storage tank of soft water treatment in-built solar energy water heater can inhibit generation of scale in the solar energy water heater and the pipeline and prolong their service life.    DETAILED DESCRIPTION - A water storage tank of soft water treatment in-built solar energy water heater, comprises a water tank, a water inlet pipe, and a water outlet pipe; where the water tank is set with a vertical insulation isolating plate for dividing the water tank into two independent spaces; the two independent spaces are respectively a soft water tank and a main water tank; the soft water tank is set with an ion exchange resin; the soft water tank is connected with the main water tank by a pipeline; the pipeline is connected with the first solenoid valve; the water outlet end of the soft water tank is connected with the lower end of the soft water tank; the lower end of the soft water tank is set with a resin injection tube; the resin injection tube is set with a second solenoid valve; the water inlet pipe is connected in series with a regenerated liquid tank; and the space between the inlet of the regenerated liquid tank and the water inlet pipe is set with a single-direction valve.    DESCRIPTION OF DRAWING(S) - The drawing shows a sectional view of the water storage tank of soft water treatment in-built solar energy water heater.