Air bubbles forming

[Fishez]

I have air bubbles forming in the sand bed and I cant figure out why or what this means, I see bubbles coming up out of the sand every few min and some bubbles are even forming on top of the sand . anybody know what this means , I set the tank up about 3 1/2 weeks ago so it still cycling but i dont remember my last tank doing this . Anybody know what this could be ?

[Fishez]

nobody knows ?

[fletch]

The bubbles in the sand are nitrogen bubbles and it is a normal part of the nitrogen cycle .......... John

http://www.reefcorner.com/Manual/nitrogen_cycle.htm

[SpngBob]

Id had my tank setup for at least 8 months and had fish and everything and I got back from vaca and there were huge bubbles on the sand.. It was a sight to see.. There was bubbles everywhere and some where midway to the top with algae keeping them from floating up.. It was really disgusting but need to look at!