An important aspect in maintaining a healthy aquarium is ensuring the water contains the right amount of oxygen. The process in which oxygen is introduced into the water is known as aeration.
Fish "breathe" through their gills. They use their gills to extract oxygen from the water that's then used and converted into carbon dioxide (just like humans) and then discharged back into the water. To ensure that there is sufficient oxygen in the water for the fish to "breathe", the carbon dioxide needs to be replaced by oxygen. This process is commonly referred to as "gas exchange" and is generally done by aerating the water. A good aeration system is therefore an essential component of any healthy aquarium.
There are two main factors when selecting an air pump for your aquarium, the maximum airflow produced and the pressure the air is produced at.
Which size of air pump you choose depends on how much air you wish to introduce into your aquarium. If you plan to use extra air outlets to drive action ornaments, bubble walls or decorative air stones, then you should consider a larger air pump. Some larger air pumps feature multiple outputs removing the need for gang valves.
When selecting an air pump for use in a deep tank you should select a larger air pump or an air pump specifically designed for deeper tanks. The reason is the deeper the water the greater the pressure the air pump meets when trying to pump air.
