Using chlorine bleach as a pool shock is not recommended as it lowers the pH level of the pool. This can lead to further algae problems and degrade the lining of the pool.
Using bleach to rid pools of algae and other problems is only a part of the solution. It is mainly a sanitizer for the pool. Overuse of bleach lowers the pH level of the pool, which can promote the growth of algae and damage the pool, causing danger to its users.
Maintaining the pool's water chemistry is the most effective way to clean a pool. Maintaining the correct pH levels, alkalinity and calcium hardness while using bleach to treat problem areas and to sanitize the water is the safest method of pool cleaning.