 The Hydor Ario air pumps are an excellent choice for those who want an in tank. They come in two versions with the difference being in size of the over all unit and the amount of air they pump. These Air pumps are also very discrete as the main unit can be buried in the gravel and just have the top showing. These units also do not require any transformer and distribute very fine bubbles in a regular column.
Hydor Ario Color air pumps are easy to assemble and and come with a suction cupped backing plate which can be used to attach the unit to the glass or they can be buried in the gravel. The rate of air can also be adjusted to via the air control valve located outside the tank. | 
