Overhead water tanks are built to cater the water needs of inmates of the house. Water tanks should be built where there is ample sun light. Lots of ready made water tanks are available in today’s market but without provision to get sunlight, it is of no good. According to vastu shastra, tanks can be built on the western side of the house avoiding the south western side. If the tank is built on the south western side, it should be seen that the water does not leak to the south eastern side and make it damp. Also the overhead tank should be at least 2 meters high from the highest part of the house. Also water tanks can be built on the southern part avoiding the south eastern area. In such cases, the roof height of the room in the south western part of the house should be higher than that of the water tank. While buying ready made water tanks, only black colored ones should be bought as they have the ability to absorb sun light. Tanks should be cleaned regularly and it should be seen that tanks get enough sunlight. Leaves and other matter should not fall in to the tank.