We do not clean ponds or lakes but an aquarium needs to be cleaned periodically. Why ?

We do not clean ponds or lakes, but an aquarium needs to be cleaned. Why ?

We do not clean ponds or lakes, but an aquarium needs to be cleaned. Why ?

Why does aquarium have to be cleaned once in a while?

(a) Natural water bodies are not regularly cleaned whereas an aquarium needs regular cleaning. Why ? (b) What are decomposers? What will be the consequence if the decomposers are completely eradicated from an ecosystem? Give justification in support of your answer.