Most swimming pool owners are aware of the need to sanitize pool water through some form of disinfection. Common chemical disinfectants for pools, like chlorine, all work as oxidizers and burn away organic matter in a pool. Some pool owners, though, try to avoid using additional chlorine when it comes to shocking a pool, so they turn to potassium monopersulfate, a nonchlorine oxidizer. "Permonosulfate," as potassium monopersulfate is often called, is a very effective pool oxidizer and works well with chlorine.
When the word "oxidizer" is used in conjunction with swimming pools, it really means that potassium monopersulfate is being used to shock a pool. Potassium monopersulfate destroys organic pool contaminants, but it also helps chlorine to do its job. For example, when potassium monopersulfate is used to shock a pool, it's actually converting useless combined chlorine back into free available chlorine. In other words, while potassium monopersulfate is eliminating odors and such, it's also increasing chlorine levels in the pool.
Shocking a pool typically involves adding even more chlorine to it, which is called superchlorination. Potassium monopersulfate pool shock is oxygen based, though, and not chlorine based. In addition, potassium monopersulfate also eliminates long waiting times before swimming can resume again after it has been used to shock a pool. With pool shocking, 8 to 12 hours must pass before swimming can resume. After adding potassium monopersulfate to shock a pool, swimming can resume once it dissipates, which is usually just a few minutes.
Potassium monopersulfate is substituted for regularly scheduled or as-needed chlorine shock treatments in swimming pools. You can add potassium monopersulfate weekly at a rate of 1 lb. per 10,000 gallons of pool water. You can also treat your pool with potassium monopersulfate more frequently if your pool is heavily used or if there has been a heavy rain or high winds. To avoid the possibility of some sort of reaction, never add two chemicals to a swimming pool at the same time.
Potassium monopersulfate is ineffective against swimming pool algae. Only chlorine-based swimming pool shock will kill pool algae after it has started growing in a pool. Also, potassium monopersulfate is acidic, with a pH of 2.3 to 3. Recommended pool pH levels should be at 7.4 to 7.6. If you use potassium monopersulfate to shock your pool, you'll also need to raise its pH levels. Raise a swimming pool's pH by adding 6 oz. of sodium carbonate per 10,000 gallons of water.
Tony Guerra served more than 20 years in the U.S. Navy. He also spent seven years as an airline operations manager. Guerra is a former realtor, real-estate salesperson, associate broker and real-estate education instructor. He holds a master's degree in management and a bachelor's degree in interdisciplinary studies.