Air bubbles?

[Lila]

My sister was cleaning her tank and said there were air bubbles coming from the rock. She was wondering if that was bad. Does anyone know?

Thanks,
Lila

[BK]

if it is a new rock it may be giving off air trapped in side pores before it was submerged.

if the tank smells like rotten eggs the gas could be hydrogen sulfide wich can harm fish. This is produced by anaerobic bacteria in oxygen deprived enviroments(under dirty gravel beds, somtimes under rocks were waste can accumulate, and in areas were water doesn't circulate well enough).

[ewok]

how long has the tank been setup?
how much vacuuming do you do?

[Lila]

She said that they vaccuum the tank about every ten days.
Tank has been there since March( I think).

Thanks.