HELP! I think I just released ANAEROBIC BACTERIA in my 75g - What do I do?

[Complexity]

I pulled out my large driftwood centerpiece from my 75g, and when I got it out of the water, I noticed the smell. I think it's anaerobic bacteria. If it is, then I just released it into my 75g FULL of fish, shrimp, and snails.

What do I do?

Do I have to pull the the fish and inverts out? Will a water change (or multiple water changes) fix it? Is there any kind of "antidote" I can add?

I know anaerobic bacteria can kill fish quickly so I'm hoping you guys can help me while I'm searching on google for answers. Thanks in advance!

[Complexity]

I'm doing massive water changes right now. That's all I know to do. I really don't want to lose all these fish after what happened to my 90g tank.

[Complexity]

I'm finding that iron can bind to the hydrogen sulfide. I have iron (and, fortunately, our water is very iron rich). But I can't find out how much iron to dose.

I've done a 70% water change. Looking for iron dosage now.

[aquabee]

Vicki, I think we should have enough iron in our water for you to not have to dose any more. Water changes and really good aeration and surface agitation would be key to help diffuse the gases out. How's everyone looking?

[mnemenoi]

Driftwood will collect and be colonized by a variety of bacteria and it will smell bad when moved out of an aquatic enviroment. As to it being anearobic, I assume some does exist on it though its likely very small amounts. I would not worry at all, there might be a small spike in your ammonia and nitrite but your other bacteria should more then compensate for it. Any time the fish or yourself move gravel or substrate they disturb anearobic bacteria and it has no ill effects. They can produce sulfide gas as a waste, but it would need to have been a very large amount indeed. Most aquarists that worry about that keep deep sand that could allow accumulation of it and it is heavier then air so it could evacuate the oxygen in a tank with a lid and cover the surface thereby polluting and possibly suffocating the tank. At least that is the theory, I myself have never seen any significant amount of sulfide gas produced (imagine a balloon sized amount...) in a tank that could threaten the life in the tank and have only sketchy and theoretical reports online.

Your water changes should be more then fine, I'd just watch and see if the inhabitants start acting strange and take steps at that point.

[mnemenoi]

http://www.skepticalaquarist.com/sulfate-sulfide-cycle

My H₂S conclusions. In sum, hydrogen sulfide could only be an issue in a substrate that was too deep (over 4 inches, say), one that was also entirely anoxic, was also depleted in nitrate and was enriched with decaying organics and sulfate, perhaps from fertilizer. Then, to get the H₂S up into the water column, though, you'd have to get in there at long intervals and vigorously stir up the deepest layers of substrate with a gravel cleaner. My point is that several poor aquaristic practices would have to be combined.

[Complexity]

Thank you both so much! I feel much better now.

I just dosed iron so that's been done whether it was needed or not. It can't hurt anything. I used the chelated iron I had from when I used to dose iron to that tank when my plants were growing like nuts. I finally found my charts of how much to dose so I used that as my guide since I know it's a safe level.

The reason I was concerned that I may have released hydrogen sulfide into the tank from anaerobic bacteria is because I didn't just move a piece of driftwood that had been sitting on top of the substrate. This was a centerpiece I had made of several pieces of driftwood screwed into a piece of slate. I had then attached filter floss on the bottom of the slate to keep it from scratching the bottom of the tank. All that had been buried under the substrate for 3 years or so. So I was pulling this from the very bottom of the tank, all the way through a very heavy layer of substrate that had not been disturbed for years.

I had completely forgotten about anaerobic bacteria until I smelled the smell. Then I realized what I had just done, and I wanted to be proactive to fix any possible problem rather than take the chance on another tank full of fish dying.

I'll keep an eye on things, but between the water change and the iron, it's my understanding that the fish should be okay even if hydrogen sulfide did get released into the water. The only concern would be if any damage occurred between the time when the incident happened and when the fresh water entered the tank. Only time will tell on that.

[mnemenoi]

Glad to hear it went well thus far! About all I can really think that might help is possibly adding on a powerhead with a good amount of air and surface agitation to increase your dissolved oxygen in the tank. I really think you'll be fine though. Most folks who use deep sand or gravel beds will stir it to avoid it forming. Apparently to form it properly it needs an enviroment completely devoid of oxygen, so occasional stirrings should avoid the issue in the future. I have even read that small chopsticks being pushed in over the area in planted tanks will do the trick. Let us know how it goes and hope its all ok!!!!

[Complexity]

http://www.skepticalaquarist.com/sulfate-sulfide-cycle

My H₂S conclusions. In sum, hydrogen sulfide could only be an issue in a substrate that was too deep (over 4 inches, say), one that was also entirely anoxic, was also depleted in nitrate and was enriched with decaying organics and sulfate, perhaps from fertilizer. Then, to get the H₂S up into the water column, though, you'd have to get in there at long intervals and vigorously stir up the deepest layers of substrate with a gravel cleaner. My point is that several poor aquaristic practices would have to be combined.

Now consider this combination:

1. Very deep substrate (3-4") for a planted tank.

2. You NEVER vacuum the substrate because you WANT the decaying organics in the substrate for the plants.

3. Then you pull up a 6" x 6" slate tile that had been sitting on the very bottom, below the substrate, disturbing the substrate on top of it and all around it.

That's the situation I just had. It wasn't due to poor maintenance, but due to the nature of a planted tank combined with my current work in rescaping the tank.

I had just totally forgotten all about anaerobic bacteria until I smelled it when I pulled the centerpiece out.

[Complexity]

I have even read that small chopsticks being pushed in over the area in planted tanks will do the trick. Let us know how it goes and hope its all ok!!!!

Which is what happens naturally when you maintain a planted tank because you are constantly uprooting and replanting plants. I do this everywhere in the tank except in the one area of the centerpiece.

Hopefully, the fish will be fine. And now I know that iron is the "antidote" to hydrogen sulfide so I learned something new out of this.

[Complexity]

Just a quick follow-up. All the fish and inverts are doing good today! So if any hydrogen sulfide did get released, the water change and iron took care of it. Whew! I'm so happy this turned out to not be a problem!

[Totenkampf]

i have experienced this as well, deep play sand bed planted tank with large driftwood. same story, it doesnt take much H2S to kill fish...I didnt have much of a bubble but it was enough to loose apistos and tetras. the good news is that it offgases quickly so water changes and water surface disruption will get things right, as you have seen. anaerobic bacteria will be present wherever nitrates are since thats what they feed on, that is what is in many of these aquarium and pond "sludge removers". i purposely added MTS to stir up the sand and that worked well. Then i added clown loaches to eat the extra MTS. its all about maintaining balance i guess lol.