Question

We do not clean ponds and lakes but an aquarium needs to be cleaned regularly. Explain

Answer 1

yes, it is
this is because, the pond has too many decomposers and turtles, earthworms, and fishes which help to keep the pond water clean.
Another big reason is that, the pond water is larger in volume hence it doesn't have oxygen debt.

Answer 2

Because Pounds and Lakes is not our property and also dependens on the country , when the country is Good and reach like America ,Qatar ,uk so you Can See there Lakes and Pounds they Are very beautiful but in india you know the condition.
and we cleaned aquarium Because its out Property and we Can See very beautiful fishes