To ensure that your aquarium water stays healthy for your pets and does not become a stagnant pool – you need an aquarium pump and learn how aquarium pump works.
Aquarium pumps are used to move the water to the surface, which allows it to interact with the air (aeration). When you Circulate and filter your the water in your aquarium tank you are obviously ensuring that the water stay does not become a stagnant and unhealthy for the inhabitants.