Detergents are more effective than soaps in hard water. Detergents are effective in acidic solutions. Demerits: excessive use of the detergents causes environmental problems. The microorganisms in water cannot decompose the components of detergents. Hence the detergents released into water lead to the destruction of aquatic life. For example, the detergents which contain phosphate increases the growth of algae and limits the quantity of oxygen. Therefore, it dej creases the quantity of oxygen for the breath of the organisms in water and causes their destruction.