What is an acceptable level of free chlorine for a spa pool?

The acceptable level of free chlorine for a spa pool is typically around 4 parts per million (PPM). This level is important because it effectively helps to kill bacteria and other harmful microorganisms present in the water, ensuring a safe and sanitary environment for users.

Maintaining free chlorine at approximately 4 PPM balances adequate sanitation without causing irritation to the skin or eyes, which can occur at higher levels. Spa water is generally warmer than typical swimming pool water, which means that microorganisms can thrive more easily, necessitating a slightly elevated level of chlorine for effective disinfection.

While other options listed, such as 5 PPM or 15 PPM, may seem to provide a more robust sanitation measure, they could lead to adverse experiences for the bathers, including skin irritation or unpleasant odors, making them less suitable for spa settings. On the lower end, 1.5 PPM may not provide sufficient disinfection, increasing the risk of waterborne illnesses. Therefore, 4 PPM represents the optimal balance for safety and comfort in spa pools.