This innovative, four-layer water tank, crafted through roto-molding, offers a superior solution for maintaining water purity and temperature stability in both homes and industries. Its design prioritizes resilience against diverse weather conditions, featuring a UV-stabilized outer layer to combat sun damage and extend its lifespan. Inside, a food-grade inner layer ensures water safety by preventing contamination. Sandwiched between these protective layers are two crucial middle layers: a foam insulation layer that regulates water temperature, minimizing fluctuations, and a black, light-blocking layer that prevents UV light penetration, effectively inhibiting algae growth and preserving water quality. This robust construction, employing high-quality materials, guarantees exceptional durability and longevity.