sandbad releasing bubbles

[carib]

hi.My 3"sandbad is releasing bubbles.Do I have a problem?thanks.

 

[Randy Holmes-Farley]

The bubbles may be O2 (from algae photosynthesizing on the surface) or N2 from denitrification taking place lower down in the sand. In either case it is not a sign of a significant problem.

I discuss denitrification here:

Nitrate in the Reef Aquarium
http://www.advancedaquarist.com/issues/august2003/chem.htm