Question

We do not clean natural ponds or lakes, whereas an aquarium or a swimming pool needs to be cleaned regularly. Why? 

Hint:

Natural water bodies are self-sustaining with natural processes for cleaning, while artificial water bodies need maintenance due to their controlled environment.

Answer 1

Natural ponds and lakes have a self-cleaning system where natural processes such as filtration, sedimentation, and biological processes help maintain water quality. However, aquariums and swimming pools are enclosed and do not have these natural processes, which is why they require regular cleaning and maintenance to prevent the accumulation of waste and maintain clean water.