Which of the following is not a water pollutant ?

Options

A. Fine sand
B. Algae
C. Fertilizers
D. CFCs

Explanation

To determine which of the following options is not a water pollutant, we will analyze each option provided:

1. **Fine Sand**:
- Fine sand can be introduced into water bodies through erosion or construction activities. While it may not be a traditional pollutant, it can affect water quality by altering habitats and affecting aquatic life. However, it is generally not classified as a harmful water pollutant.

2. **Algae**:
- Algae are organisms that thrive in water, especially when nutrients are abundant. When algae grow excessively, they can lead to algal blooms, which deplete oxygen in the water and can produce toxins harmful to aquatic life. Thus, algae can be considered a water pollutant.

3. **Fertilizer**:
- Fertilizers are chemical substances used in agriculture to promote plant growth. When fertilizers run off into water bodies, they can cause nutrient pollution, leading to problems like algal blooms and eutrophication. Therefore, fertilizers are classified as water pollutants.

4. **CFCs (Chlorofluorocarbons)**:
- CFCs are chemicals primarily used in refrigeration and aerosol propellants. They are known to cause air pollution and contribute to ozone layer depletion. CFCs do not directly pollute water bodies, making them unrelated to water pollution.

Based on this analysis, the option that is not a water pollutant is **CFCs**.

### Final Answer:
CFCs (Chlorofluorocarbons) are not a water pollutant.