Caliban07
Aquarium Advice Addict
Resurrecting this old thread. Most of it addresses cleaning the sand surface. But over time stuff does work it's way in. I read about sand going anaerobic and wondering what the do to keep that from happening short of turning MTS loose in the tank.
I'm certain I have read a number of threads that say once the pocket of hydrogen sulphide escapes in to the tank it is immediately oxidised in to sulphates and is therefore harmless to livestock. I would be concerned about plant roots but even a healthy plant should have no trouble keeping the sediment oxygenated around the roots/rhizosphere. Any other non smelly bubbles could just be co2 escaping.
I'll see if I can drag some links about H2S.