Certified Pool Operator Practice Test

The humidity levels for indoor pools and spas should be maintained between 30 to 50%. This range is recommended in order to maintain a balance between preventing moisture-related damage and maintaining a comfortable environment for pool and spa users. Humidity levels that are too low can cause damage to the building and equipment while levels that are too high can cause discomfort for users and promote the growth of bacteria and mold. Options B, C, and D all exceed the recommended range and could potentially cause issues. Therefore, option A is the best and most accurate answer.