Shocking your swimming pool is a very important element in maintaining your pool water’s clarity and balance. Using chlorine tablets alone will not kill off all bacteria and algae that grow in the pool water. Also, the chlorine tablets have a very low PH level, and their overuse will lead to a low PH, which is very dangerous to the pool, and its users. By shocking the pool each week, you will be quickly raising the chlorine level, which will rid the pool of contaminants, without lowering the PH of the pool water.