Question

How phitkari helps in water clear

Answer 1

Alum(phitkari), when added to raw water reacts with the bicarbonate alkalinities present in water and forms a gelatinous precipitate. This floc attracts other fine particles and suspended material in raw water, and settles down at the bottom of the container. The water over this sediment is almost clean other than some fine particles dissolved in it. Alum is in a crystallized form which you can powder and store in a clean glass container.

most of this you will learn in the higher classes.