An aeration device or diffuser is disclosed. The diffuser preferably includes a porous hose adapted to allow gas to escape therefrom, a rigid element disposed within the hose, the rigid element being constructed of material denser than water and a fitting suitable for attaching the hose to an air supply, the fitting disposed within the hose at one end of the hose. Methods of use of the diffuser and of assembling the diffuser are also disclosed.