Explanation:

Mud balls are formed in filters due to insufficient washing of sand grains. When sand grains are not washed properly, the impurities in the sand can form clusters, creating mud balls. These mud balls can clog the filter and reduce its effectiveness.

Factors contributing to mud balls formation:

1. Incomplete washing: When sand grains are not washed properly, the impurities in the sand can form clusters, creating mud balls.

2. High turbidity: High levels of turbidity in the water can lead to the formation of mud balls.

3. High organic content: Water with high organic content can also contribute to the formation of mud balls.

4. Poor filter design: Poor filter design can lead to inefficient washing of sand grains, which can contribute to mud ball formation.

Effects of mud balls:

1. Reduced filter efficiency: Mud balls can clog the filter and reduce its effectiveness, leading to reduced water flow and quality.

2. Increased maintenance costs: Mud balls can increase maintenance costs as they need to be removed manually.

Prevention:

1. Proper washing: Proper washing of sand grains can prevent the formation of mud balls.

2. Regular maintenance: Regular maintenance of filters can help prevent the formation of mud balls.

3. Use of coagulants: The use of coagulants can help reduce the formation of mud balls by reducing the amount of impurities in the water.

Conclusion:

Mud balls are formed in filters due to insufficient washing of sand grains. Proper washing of sand grains, regular maintenance of filters, and the use of coagulants can help prevent the formation of mud balls, which can reduce filter efficiency and increase maintenance costs.