Question

Generally , we do not clean natural ponds or lakes but an aquarium needs periodic cleaning . why?

Answer 1

Answer:because the fishs would die.

Explanation:

Answer 2

Answer:

We do not clean ponds or lakes , but an aquarium needs to be cleaned. ... In the Aquarium the uneaten food as well as the waste generated by the fishes mixes with the water and is left untreated due to the lack of decomposers. The waste materials thus accumulate in the water making it toxic

Explanation: