how to check residual chlorine in water

How to Check Residual Chlorine in Water

Clean water is essential for our survival, and chlorine is a vital component that helps keep our water supply safe to drink. Municipal water treatment plants add chlorine to our drinking water as a disinfectant to eliminate harmful bacteria, viruses, and pathogens. However, too much chlorine in our water can be dangerous and cause health issues. Therefore, it's crucial to check the residual chlorine levels in your water to ensure it's safe for consumption.

In this article, we will discuss what residual chlorine is, how it affects our health, and various methods to measure the level of residual chlorine in water.

What is Residual Chlorine?

Residual chlorine is the remaining amount of chlorine in water after adding enough to disinfect it. Chlorine is rapidly consumed by organic materials present in water, so health authorities mandate that a certain amount of residual chlorine should remain in the water supply to ensure it remains disinfected until it reaches the customer.

The amount of residual chlorine required in water depends on the climate, microbiological activity, temperature, pH, and water usage rate. Typically, the recommended level of residual chlorine in water is between 0.5 and 1.5 mg/L.

Health Effects of Excess Chlorine

While chlorine is an essential disinfectant, excessive amounts of it can cause health issues such as skin irritation, respiratory problems, and digestive discomfort. Moreover, research shows that prolonged exposure to chlorine in drinking water can increase the risk of certain cancers such as bladder, colon, and rectal cancer.

Methods to check Residual Chlorine in Water

1. Chlorine Test Kits

Chlorine test kits are an easy and affordable way to check the residual chlorine levels in water. These test kits come in various forms, including test strips, liquid reagents, and droppers. Test strips are the most common and convenient, as they only require dipping the strip in water and comparing the color change to the provided reference chart. Test kits can give you an estimate of the residual chlorine levels in water, but they are not as precise as laboratory testing.

2. Portable Chlorine Meters

Portable chlorine meters are more accurate and precise than test kits and are primarily used for industrial and commercial purposes. However, they are also available for home use, and they offer more reliable measurements of residual chlorine levels in water. Portable chlorine meters use advanced electrochemical sensors to detect chlorine levels in water and provide instant readings.

3. Lab Testing

For the most accurate and reliable residual chlorine readings, lab testing is the best option. You can collect a water sample and send it to a certified laboratory for analysis. Lab testing also provides additional information such as pH, turbidity, and water hardness, which can affect chlorine levels.

4. Smartphone Apps

Smartphone apps are a more recent technology that utilizes the camera's colorimeter to measure residual chlorine in water by analyzing the color change of a test strip. These apps are suitable for home use and provide quick and easy readings of residual chlorine levels in the water. However, their accuracy may vary depending on the app's calibration and the phone's camera quality.

5. Visual Inspection

While not technically a method of checking residual chlorine in water, visual inspection can help you identify the presence of chlorine in water. Chlorine gives off a distinct smell and taste that indicates its presence in water. However, this method is not precise and cannot give you the residual chlorine levels accurately.

In conclusion, checking the residual chlorine levels in water is crucial for safeguarding your health and ensuring the water's safety for consumption. A combination of these methods can be used to get a more precise reading and ensure your water is free of excess chlorine.