The amount of bleach used to shock a pool depends on the size of the pool. Shocking a pool requires increasing the chlorine to 5 parts per million. This means you need 1/2 gallon of bleach for every 10,000 gallons of pool water.
Shocking a pool means to add a type of oxidizing chemical, such as bleach, to the pool in order to destroy organic contaminants and ammonia. It also helps control bacteria and algae in the pool.
To determine a pool's capacity, start with the pool's measurements. Multiply the pool's length by its width. Multiply that number by the pool's average depth. Then multiply that number by the proper multiplier for your pool's shape: 5.9 for oval or round and 7.5 for a square, rectangular or free-form pool.