Air stones are used with an air pump to oxygenate the water, creating a healthy environment for plants and fish. The stone ball creates an abundance of fine bubbles Air stones are a must-have when growing hydroponics as the plant roots thrive with the oxygen supplied by the air stone. Not only does the air stone fill the tank with tiny oxygen-filled bubbles, but it also helps to circulate the water. Oxygenate water Improve water circulation