How truly dangerous are gas pockets in sand?

[eco23]

I'm pretty good about stirring my sand substrate during pwc's every week...but today I uncovered a fairly large black patch in a corner of the aquarium.

My immediate response was to throw the Python on full blast, and I sucked up the entire area (lots of sand in the pipes I'm sure). Obviously it was a gas, not the sand which was the problem...but hopefully it removed the pocket of gas as it was sucking up the substrate.

I've seen lots of differing information online, everything ranging from these hydrogen sulfide pockets being instantly deadly, all the way to them being harmless since the oxygen in the tank handles it in seconds.

Does anyone have personal experience with death or illness caused by these gas pockets...or is it a danger perhaps over-exaggerated?

*BTW, I'm using PFS about 2 1/2 inches deep, stirred weekly. I also have deep rooting plants. The black area was maybe 2' x 2", so fairly large.

 

[mfdrookie516]

I assume that the bubbles I see coming up out of my dirt tanks are hydrogen sulfide. They smell like a fart after eating boiled eggs. Everything I've read says they're instantly 'safe' after hitting oxygenated water. I've not had any die off from the bubbles coming up out of my tanks. Some of them were pretty big bubbles too.. one made a crater in the substrate about 6" in diameter and stirred up the biggest bunch of mucky mess in the world (from the dirt).

This, unfortunately, is one of those things like NTD or DGD... if fish die, that's to blame. Just like diatoms and PFS.

 

[eco23]

Surprisingly there weren't any bubbles or odor, but the Python may have handled it before it escaped.

I'm leaning the same way that the threat is overblown and people just like to create panic. I guess I'll stick with that opinion as long as everyone doesn't go belly-up in the next few hours, haha.

I'd think that if there really was a significant danger...we'd see a lot more people sharing experiences of their fish dying rather than just claiming these pockets are deadly based on what they've heard.

 

[Mumma.of.two]

I assume that the bubbles I see coming up out of my dirt tanks are hydrogen sulfide. They smell like a fart after eating boiled eggs. Everything I've read says they're instantly 'safe' after hitting oxygenated water. I've not had any die off from the bubbles coming up out of my tanks. Some of them were pretty big bubbles too.. one made a crater in the substrate about 6" in diameter and stirred up the biggest bunch of mucky mess in the world (from the dirt).

This, unfortunately, is one of those things like NTD or DGD... if fish die, that's to blame. Just like diatoms and PFS.

I have the same thing in my dirt tanks. I see bubbles daily. I've only smelt a really bad odor a couple of times and no fish deaths from it.