How Aquarium Aeration Works
In the hobby of keeping fish, many pet owners strive to make their aquariums mimic the natural environment of their fish as closely as possible. In nature, lakes, rivers, and oceans are able to support huge populations of fish, invertebrates, and aquatic plants in varied volumes of water. Because of their enormous surface area, oxygen producing plankton, and many plants, these natural environments can easily recycle the oxygen needed for large numbers of fish.
In the aquarium, aeration works quite differently. There are usually small surface area to volume ratios which makes the balance of oxygen different. In most cases, the majority of oxygen in the fish tank is thanks to the steps the tank owner takes to keep the fish alive and thriving. Aquarium aeration is the process we take to keep a healthy supply of oxygen in the tanks for our fish!
In many fish tanks, the oxygen/air is provided by a combination of a filter and air pumps. Most filters cause at least some of the surface water to flow and be disturbed. Some even cause bubbles of air to be sucked down into the aquarium. Either way, this disruption of the water surface improves the exchange of oxygen between the air and water. If you have seen those well known aquarium decorations that have bubblers built in (like divers, sunken treasure chests and others) they serve two purposes. Besides keeping fish and owners entertained, they also directly inject air into the water column, sometimes through diffusers which break up air bubbles into dozens of smaller bubbles. As the air rises in the water, oxygen diffuses into the water while carbon dioxide fills up the bubble.
Overall, many steps must be taken to ensure an adequate balance of water in the fish tank. Aquarium aeration is perhaps one of the most vital steps in keeping tropical and marine fish healthy.