# regarding bacteria and the nitrogen cycle



## pH7 (Dec 5, 2011)

I'm looking for some concrete information about what I only know in anecdotal and internet-learned fashion.

As I understand it, a certain anaerobic bacteria consumes ammonia in the water, the bi-product of which is nitrite. Thereafter, a type of aerobic bacteria consumes the nitrite and the bi-product of that is nitrate.

What I'm trying to find out is:


Is this true? Are there truly two types of bacteria responsible for the full nitrogen cycle?
Are the bacteria, as described, correspondingly aerobic for the first stage and anaerobic for the second?
What are the names of the bacterium types?


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## fauxcive (Nov 25, 2011)

I can't tell you specific names of bacteria (as I understand, even from civil engineers, this is in question), but there are generally two types (more accurately two clusters of types). Most noteworthy is that those that decompose nitrites cannot replicate in the presence of ammonia, ergo they rely heavily on those that feed off ammonia... which results in a very long cycle. The difference is noticeable however, and there are (from my experience) two phases of "cloudy" bacterial blooms, the latter of which lasts significantly longer. Based on that information, yes, I believe it to be true. Whether they be aerobic or anaerobic is really inconsequential, since the results of both (and the timeline) is roughly the same. I'm banking on both of them being aerobic though, since they are both prolific in a well aerated tank. Bacteria that feed off of the end-resulting nitrates however, seem to be more anaerobic (I base this entirely off of personal school study, and nothing to take seriously). Hope that helped?


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## Gizmo (Dec 6, 2010)

The two types of nitrifying bacteria that are commonly referred to are nitrospira and nitrosomonas. The nitrosomonas are responsible for metabolizing NH4 (ammonia) into NO2 (nitrite), and the nitrospiras are responsible for metabolizing NO2 into NO3 (nitrate).

To the extent of my knowledge both nitrosomona and nitrospira are aerobic bacteria, so they benefit from things like bubblers and power filters that create surface agitation and move a lot of water around. They also live in the substrate.

There is a third type not many people talk about because they affect fresh water aquariums much less than, say, a deep sand bed marine tank. They are the anaerobic nitrifying bacteria you speak of (I'm not sure the name), but they consume nitrate and sulfate and produce hydrogen sulfide gas, amongst other things. They are dangerous because those hydrogen sulfide gas pockets build up in the substrate and can bubble up and "explode" into the tank, causing cataclysmic tank crashes. They are rare in freshwater planted tanks because plant root systems consume the nitrate and sulfate sequestered in the substrate before the anaerobic bacteria can, and also because in general there is more water circulation through the substrate in a freshwater tank, especially with an under gravel filter. Take note: hydrogen sulfide gas only becomes a problem in marine tanks after the course of years, and most freshwater tanks aren't up for years without some changes.

Source:
The Aquarium Nitrogen Cycle

Hope this helps!


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## pH7 (Dec 5, 2011)

Gizmo, fauxcive,

I wanted to thank you for taking the time to put together those great replies. I know it meant time out of your day, so I appreciate you reaching out across the internet to a fellow aquarist and indulging my itch to learn more.

I read the fish lore article you cited, as well as another article I found at a different website that was much longer, and extremely in-depth. I'm trying to find the link... I just printed it out to read it since it was so long. If I can find the link I'll post it. It was a great article and it coincided with what you are saying.

The primary benefit I'm deriving now from all my research, as far as I am able to understand it, is one sound nugget of aquatic wisdom: you need *autotrophic* bacteria for a long term cycle, while the *heterotrophic* bacteria in practically all available pet-store "bacteria in a bottle" products provide only a temporary fix and out-compete already-present autotrophs because their reproduction rate is so unbelievably fast; sadly, so too is their die-off rate (translating to more ammonia and you're back to square one after a short-lived pseudo victory.)

Right now, during the cycling of my newest aquarium, my chosen path is to avoid the "quick fix" products and either wait it out while the truly beneficial bacteria colonies slowly grow, or find some seeded filter media from a friend. My only problem with the latter option is that I don't have any nearby friends who keep aquariums and my LFS won't give me anything either-- their decision, I have to live with it; the bright side is that while I won't get any beneficial bacteria from them, I won't get any pathogens either 

Again, thank you so much.


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## pH7 (Dec 5, 2011)

PS- I've found out both through reading and mistakes that:

the effect of lowering pH with tannins leached from impatiently introduced driftwood slows down the establishment of the bacterium types that depend more heavily on inorganic carbon (because tannins lower KH). If memory serves me, these are the nitrobacter (nitrospira) bacteria as opposed to the nitrosomonas.
lower-temperature goldfish tanks cycle slower because the bacteria tend to thrive in warmer tropical temperatures. This is a catch-22 for newbies who follow PetSmart's written advice (literally, it comes printed on PetSmart's in-house brand aquarium kit instructions) to cycle with fantail goldfish. They don't even mention fish-less alternatives.
Thank goodness for SeaChem Prime!
I need to make some _local_ aquarium buddies


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## beaslbob (May 29, 2009)

pH7 said:


> I'm looking for some concrete information about what I only know in anecdotal and internet-learned fashion.
> 
> As I understand it, a certain anaerobic bacteria consumes ammonia in the water, the bi-product of which is nitrite. Thereafter, a type of aerobic bacteria consumes the nitrite and the bi-product of that is nitrate.
> 
> ...



In a word no. aerobic bacteria are responsable for ammonia to nitrite and nitrite to nitrate. Which is what is commonly taught. From that point anoxic(low oxygen) or anaerobic (very low oxygen) bacteria can reduce the nitrates to nitrogen gas (hopefully) or ammonia (not hopefully) of various sulfur compounds (really dreaded).


> [*]Are the bacteria, as described, correspondingly aerobic for the first stage and anaerobic for the second?


the first two setps above are aerobic.


> [*]What are the names of the bacterium types?



the names are too big for me to spell. *old dude

One thing that is not commonly taught but is part and parcel of the nitrogen cycle is that plants play a huge role even if just various forms of algae. Most plants actually prefer to consume ammonia directly and will do so if availible. Then as the aerobic bacteria build up the plants start consuming the resulting nitrates for nitrogen.

Just to make it even more complex some forms of plant life act like soybeans in farmers fields in that they "fix" nitrogen from the nitrogen gas in the water. This can happen when the tank becomes nitrate starved but still has phosphates. These include some black algae and blue green cyano bacteria. With limited lights the cyano dies off which returns nitrates for the more "normal" plants. (which is actually somewhat similiar to farmer rotating crops so the soybeans return nitrogen to the soil for next year's wheat or corn)

all in all just what I've heard on the net. 

worth at most .02


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## Gizmo (Dec 6, 2010)

pH7 said:


> PS- I've found out both through reading and mistakes that:
> 
> the effect of lowering pH with tannins leached from impatiently introduced driftwood slows down the establishment of the bacterium types that depend more heavily on inorganic carbon (because tannins lower KH). If memory serves me, these are the nitrobacter (nitrospira) bacteria as opposed to the nitrosomonas.
> lower-temperature goldfish tanks cycle slower because the bacteria tend to thrive in warmer tropical temperatures. This is a catch-22 for newbies who follow PetSmart's written advice (literally, it comes printed on PetSmart's in-house brand aquarium kit instructions) to cycle with fantail goldfish. They don't even mention fish-less alternatives.
> ...


Neat info on the tannins. If you can get links to your sources I'd love to file them away for reference later.

PetsMart, PetCo, and especially WalMart are the bane of most educated fishkeepers` existences, because of #1 the average knowledge base of their sales clarks, #2 the way they treat their fish, and #3 the misleading and often outright incorrect information they feed new uneducated fishkeepers. Local Fish Stores (LFS's) are the way to go, but often even those are found wanting.

As far as local buddies, where are you located? In Utah, we have Aquatic Utah • Index page, UTMAS (Utah Marine Aquatic Society), GSLAS (Greater Salt Lake Aquarium Society), and there's a neat little Utah section on The Planted Tank forum.


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## pH7 (Dec 5, 2011)

Gizmo said:


> Neat info on the tannins. If you can get links to your sources I'd love to file them away for reference later.


Finally found it! Gaaah! I had done so much reading I couldn't find the one that had been most informative because it was buried in search engine listings. Here it is: Aquarium Nitrogen Cycle and cycling. Methods for ammonia, nitrite removal.

If you read deep into the essay it talks about the influence of pH (ergo the "tannins" comment from me).

Also, in the text of the essay its author mentions the "Stability" product from SeaChem as an aid in cycling, or at least as a quick-fix for ammonia/nitrite control when introducing new fish. But like I said previously, based on everything I've gathered from my own experiences and extensive reading (including that very essay), I'm not going to make use of SeaChem Stability or anything of its ilk. The very nature of the product and its years-long shelf life belie the "synergistic blend of bacteria" claims made by the manufacturer, given that only hetertrophs (compared to autotrophs) can live that long without requiring refrigeration or a food source. That doesn't sound very synergistic, or very blend-y at all. Looks much more like a one-trick pony.

So why the hesitation to use heterotrophic bacteria in a bottle? Because I'm afraid of it out-competing what little autotrophic bacteria that have already successfully built up in my filtration systems. Paranoid much? Well, I don't know, because there's no truly conclusive studies about who wins and who loses in such a battle of bacteria (the autobots or the heterobots).

And finally, speaking to the issue of the great length and depth of that essay (over twenty pages printed): Since I'm a hard core nerd, the in-depth explanations in that essay may have appealed to me more than they would the average Joe, but I can't be sure. After all, I am a nerd. I enjoyed that formal write up more than any other I could find and have now safely tucked it away in my browser bookmarks of awesomeness.



Gizmo said:


> PetsMart, PetCo, and especially WalMart are the bane of most educated fishkeepers` existences, because of #1 the average knowledge base of their sales clarks, #2 the way they treat their fish, and #3 the misleading and often outright incorrect information they feed new uneducated fishkeepers. Local Fish Stores (LFS's) are the way to go, but often even those are found wanting.


YES! And to really affirm my point and provide real proof, I literally went and dug up the instruction manual from PetSmart's (in-house brand) TopFin aquarium kit which I purchased for the purpose of a small hospital tank and opted to buy the kit instead of a bare tank due to a special they were running for the holidays. I took a picture... a snapshot of shame. Here it is:











Gizmo said:


> As far as local buddies, where are you located? In Utah, we have Aquatic Utah • Index page, UTMAS (Utah Marine Aquatic Society), GSLAS (Greater Salt Lake Aquarium Society), and there's a neat little Utah section on The Planted Tank forum.


I looked it up, and I'm sitting 999'ish miles southeast-erly from you, as the airliner flies. Not exactly *local* heh heh. Still, I appreciate the sentiment!


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## beaslbob (May 29, 2009)

PH7


+1.

to me here is the bottom line. *fast growing thriving plants make everything else including aerobic bacteria irrelevant*.

Then as the bacteria build up they also consume the nitrates, phosphates, nasty ions, carbon dioxide while returning oxygen and fish food.


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