bubbles on rocks

[salineh2o]

Why are there always bubbles on my rocks?

 

[salineh2o]

(Pardon)

 

[rustybucket145]

Any pics?

 

[skeeter-doc]

could be anything

microbubbles from your skimmer/return, ...
bubbles from the nitrogen cycle in your tank, ...
air bubbles caught underneath your rocks when first introduced, ..