Certified Pool Operator Practice Test 2026 – Comprehensive Exam Prep

Testing for total chlorine and free chlorine and then subtracting the free chlorine number from the total chlorine is the most accurate and reliable way to determine the level of chloramines in pool water. This is because chloramines are a combination of total chlorine and free chlorine, and by subtracting the free chlorine value from the total chlorine value, you are left with the amount of chloramines present in the water. Options A and B are incorrect because they do not take into account the presence of chloramines. Option D is also incorrect because it simply adds the two chlorine readings together, which does not accurately reflect the level of chloramines.