Water tanks play a vital role in water management and rainwater harvesting. However, conventional options have significant drawbacks. Concrete tanks are expensive, require skilled installation, and are difficult to repair if cracked. Poly tanks are more affordable but bulky to transport, hard to clean, and non-repairable once fractured. They also offer poor thermal insulation, causing stored water to overheat beyond 50°C in summer, often rendering it undrinkable. Both solutions fall short in cost, durability, and usability, particularly when scaled up or used in extreme climates.