Superchlorinating a pool is the process of sanitizing the pool water by adding large amounts of chlorine to it. While pool water is usually chlorinated as it is, superchlorination increases that amount to further eliminate germs and bacteria from the pool. Chlorine is a very effective sanitizing agent since bacteria cannot survive in a chlorine environment.
Refill your chlorinator with chlorine pellets and turn the dispersal to "full" so the chlorine gets absorbed into the water as quickly as possible.
Pour pool shock into the pool through the skimmer. Pool shock is a heavy dose of chlorine designed to rapidly raise the pH level of the water to prevent algae and bacteria growth. The amount depends on the size of the pool and the severity of the current state of bacteria or algae in the water. A 15,000 gallon pool generally needs 1.5 gallons of shock treatment to elevate the chlorine to acceptable levels, usually 10 ppm.
Avoid swimming in the pool while it is superchlorinated. High levels of chlorine are toxic and the water should be tested prior to re-entering the pool following a shock treatment. No one should swim until the chlorine level is about 3 ppm or less.