After raising the free chlorine level post-accident, how long should the pool remain closed?

The appropriate time to keep the pool closed after raising the free chlorine level post-accident is 24 hours. This ensures that the elevated chlorine levels have enough time to effectively sanitize the water and eliminate any harmful pathogens that may have been introduced during the incident. Keeping the pool closed for this duration allows the chlorine to maintain its efficacy and ensures both safety and health for all swimmers.

Shorter closure times, such as 5 or 25 minutes, are insufficient for the chlorine to do its job effectively. Chlorination requires a designated period to ensure that contaminants are neutralized completely. A 12-hour closure could still be too brief, especially in the case of a severe incident, as the chlorine needs to stabilize and adequately bring the water back to safe sanitation levels. The 24-hour closure period fully accounts for the necessary chemical processes involved in pool sanitation following an accident.