What is a sign that chlorination may be necessary in a pool?

The presence of algae in a pool is a clear indication that chlorination may be necessary. Algae grow in stagnant or improperly sanitized water, and their appearance signifies that the current levels of sanitation are insufficient. Chlorination is crucial for controlling algae growth and maintaining a clean, safe swimming environment. By elevating the chlorine levels, the pool operator can effectively eradicate the algae and prevent it from returning, ensuring the water remains clear and healthy for users.

In contrast, clear water typically indicates that the pool is well-maintained, while a strong chlorine smell could suggest an imbalance related to combined chlorine rather than the need for additional chlorination. Balanced pH levels are essential for effective chlorination but are not a direct indicator that chlorination is necessary.