A bubbler is another name for an air stone, a device that creates bubbles in an aquarium. While not every aquarium has one of these, it can provide valuable benefits for the aquarium and its inhabitants. The bubbler connects to a length of plastic tubing whose other end connects to an air pump, which pumps air through the tubing and out the air stone, creating the bubbling action. When deciding whether or not to add a bubbler to your aquarium, take into account a few factors.
One of the prime purposes of a bubbler in an aquarium is to increase the amount of oxygen dissolved in the water. Adequate oxygen is essential to the survival of the fish in the tank, and the bubbling action increases the amount of oxygen by breaking the surface tension of the water. This allows for improved absorption of oxygen, increasing the amount available to the fish. Tanks without a filtration system or that have more than the optimal number of fish will benefit from a bubbler.
The use of a bubbler in an aquarium can add to the overall beauty of the setting. In some cases the bubbles may operate certain decorations such as faux divers and treasure chests, or air stones are set up to create sheets of bubbles that create interesting underwater effects. These create focal points in the aquarium and are particularly fun for children.
In addition to adding oxygen to the water, the bubbling action of air stones helps to remove unwanted gases, particularly carbon dioxide, from the water. As the bubbles rise, they tend to carry carbon dioxide with them, which leaves the water when the bubbles pop. This promotes a healthy, stable pH level in the tank, since high levels of carbon dioxide tend to lower the pH; by removing carbon dioxide, the bubbling action helps the pH to stay constant.
Despite the fact that certain fish live in stagnant water in the wild, stagnant water in the incomplete ecosystem of an aquarium can be fatal. Such water forms layers of various temperatures, the top will develop a filmy skin that traps bad gases in and oxygen out, and the conditions will typically favor problems such as heavy algae growth and disease. The bubbler helps to keep everything circulating so that the water can't stagnate, though the larger the tank the less effective a bubbler is for this purpose.