Liquid shock is 12.5% sodium hypochlorite. Clorox bleach is 3% sodium hypochlorite. Although they are made of the same chemical, the percentage of chlorine in shock is much greater than Clorox bleach. To treat a 20,000-gallon pool, you would need to use two bottles of liquid shock. To achieve the same amount of chlorination with bleach, you would need to use eight bottles. Additionally, Clorox bleach contains added detergents, which could interfere with the chemical balance of your pool.