Answers

2015-06-01T00:26:17+05:30
 A pond or a lake has its own natural system of cleaning the waste materials to maintain its ecosystem. Due to this, ponds are lakes normally do not need to be cleaned. An aquarium is a man-made ecosystem which has a very small space. The abiotic components are not supplied naturally to the aquarium. So, an aquarium needs frequent cleaning so that the living beings in it can survive.

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