Dangerous Bubbles?

[maaltan]

There is a difference in solubility of the gases being discussed. Even undisturbed anoxic areas are relatively harmless while undisturbed, but there can be some diffusion of toxic materials into the water column, and greatest risk is to the substrate dwellers. Disturbing an axoxic and H2S-loaded area can wipe out much of a tank. Such does get reported here periodically. Consider it a time bomb, and as such not a good thing to have in your tank.

But I do agree that the bubbles seen in the original post are more likely O2.

hmm great ... more stuff to worry about soooo if you were to happen to get one of these how would you safely get rid of it? do as mentioned before and suck it up with the gravel cleaner? sounds risky if it can do so much damage if you screw up. I guess prevention is the important issue here.

 

[wataugachicken]

i would start off by reducing your sand down to a half inch or so. even if you're worried about losing your good bacteria, they won't live in the deep parts where they can't get oxygen, just in the uppermost area. then make sure that you poke around in it when you're messing with your tank so that no area stays undisturbed (able to build up bad stuff) for too long.