What is an air release for a Fish Tank?

This is a small block, usually of porous stone, which serves to break the air passed through it into small bubbles. The quality of the stone is judged by how small a bubble it can produce, while at the same time offering a minimum of resistance to the passage of air.

Reeds are frequently used as aerators. While not particularly efficient, they have the merit of being inexpensive. There are several chrome and stainless-steel aerators on the market today. They use a felt or nylon disc to break up the air. They have an adjustable screw which, by compressing or releasing the fibrous disc, allows smaller or larger bubbles to escape. There are also a number of so-called ornamental air releases on the market, such as divers, frogs, mermaids, etc. If they are efficient, if you like them and they are not made of toxic materials, by all means get one.

The purposes of aeration are many, for example, to circulate the water gently, thus providing even temperature, and to make filter operation more effective. The prime purpose of aeration, however, is to drive off the carbon dioxide and allow a greater absorption of oxygen.

A certain amount of oxygen is absorbed from the bubbles as they rise through the water. By far the most effective action takes place at the surface, however. It is the agitation on the surface that gives the best results. As a practical matter, any agitation of the surface will produce the desire results. A small paddle, an electric fan blowing over it, or a drip of water all will aerate the water. A filter also provides a good deal of aeration.

Best results are obtained from a fairly small bubble. A fine, misty bubble does not agitate the water enough. A burst of large bubbles may agitate it too much; also, efficiency is lost with the larger bubbles, since less surface area is being presented to the water for operated; only one valve is necessary. This must be a three-way valve; that is, one with three outlets of those connections. The threaded screw controls the opening of the center outlet. The two opposing valves are a by-pass, always remaining open. The square flat tab is usually slipped under the edge of the tank, in back, where the weight of the tank holds it in place. An air tube connects the pump to one of the by-pass outlets. Another piece of flexible plastic tubing connects the center outlet to the air-lift tube, and the aerator is connected to the remaining outlet.

The air, of course, takes the path of least resistance. With the valve opened, all the air will pass through the filter, as this offers less resistance to the passage of air. By slowly closing the valve, air will be held back and will seek an outlet through the aerator. Adjust the valve to assure an even flow of air through the aerator. Fishes do not like to live in a storm, so it is good practice to maintain only a gentle flow of air.

To connect a greater number of outlets on one or more tanks, use a three-way valve for each outlet required, a two-way valve at the end. The opposing arms are used to continue the line, with the filter or aerator always connected to the center outlet. Although it is convenient to slip the tab under the base of the tank, it is more practical to fasten the valves to a point above the tank. This eliminates the possibility of water siphoning back through the air line.