This paper discusses the magnetic powers on the thermosolutal convection of nano-encapsulated phase change material (NEPCM) inside a porous annulus by using the ISPH method. A novel annulus is constructed between an exterior hexagonal-shaped and inner shape of the dual curves having varying lengths (a&b). The heat/mass source is put in the left-top and right-bottom parts of a hexagonal-shaped and the other parts are adiabatic. The inner dual curves are maintained at Tc and Cc. The effects of the inner dual curve lengths (a=0.1−0.4&b=0.2−1), a fusion temperature (θf=0.05−0.95), Darcy parameter (Da=10−2−10−5), Hartmann number (Ha=0−100), solid volume fraction (ϕ=0.01−0.06), time parameter (τ=0−0.8), and Rayleigh number (Ra=103−106) on the contours of heat capacity, concentration, streamlines, temperature, and nanofluid velocity are researched. The results revealed that an increase in a fusion temperature shifts a phase change zone from the dual curves towards the heater source positions. The lengths of the inner dual curves are controlling the contours of the heat capacity, temperature, streamlines, and concentration in an annulus. Thus, the velocity's maximum boosts by 26.92% as length b shrinks from 1 to 0.2. Increasing Ra expands the contours of temperature, concentration, and heat capacity Cr across an annulus.