The cost of water tank cleaning services differs based on the tank capacity. For regular overhead and Sintex tanks, if the tank capacity is up to 1000 liters, the price charged is around 799/-. The prices charged for 3000-6000 liter and 6000-10,000 liter tanks are 999/- and 1,200/- respectively. However, prices may still differ from one service provider to the other.