Nitrosomonas bacteria, Nitrogen Cycle


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In this part of the website, you will also find out how to take care of algae problems, what to feed your fish, what the proper water parameters are, and many other good techniques to keeping your fish and invertebrate happy and healthy. With this information, members will have a much better understanding of keeping their tank in top condition.

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One characteristic, next to passion for the hobby, every aquarist should have or obtain, is patience.

Patience, next to understanding the basic water parameters, will be put to the test while cycling a tank. And cycling by all means, not only during the fresh set up of a new tank. An established aquarium can cycle at any time, depending on severe changes of the bioload, filtration failure, or any loss of nitrifying bacteria, or adding new animals.

The cycling process starts the aquarium. Since an aquarium is an artificial and fragile ecosystem it requires our “interference” in order to thrive. Our interference starts with providing an “artificial” filtration system. In short, creating an environment as close to nature as possible.

This cycle also occurs when the tank becomes out of balance. If waste levels become too high, because of over-feeding, overstocking, and/or lack of water changes, ammonia levels will rise again. In this case, water changes should be performed until normal levels are restored.

This cycle can occur when the bacteria that breakdown organic wastes die. This can occur when the tank or filter is washed with soap or some disinfectant. If this occurs, the tank will have to be cycled again. Be aware that too acidic (below 5.5 pH) water or some medications can also deplete the bacteria population.

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New Tank Syndrome, or

Cycling a Aquarium after adding new animal life to the established  aquarium.

Aquarium Doctor

"nitrosomonas bacteria"

Nitrosomonas is the first bacteria the Nitrogen Cycle produces to remove the organic waste product ammonia from concentrating in an aquarium. nitrosomonas is a lithotrophic bacteria that requires clean, hard surfaces to attach its population to. It is aerobic, requiring an adequate supply of oxygen to sustain its life cycle as well. Most often, these bacteria are cultured in filters which provide the clean hard surfaces they need to attach to. The nutrients provided by the water as it flows through the media are normally suitable to produce enough of a population to remove all the ammonia from the aquarium as soon as it is produced by the fish and decay processes..

"nitrobacter bacteria"

This is the lithotrophicbacteria that nature has created to reduce nitrite after it has been produced by nitrosomonas bacteria. nitrobacter is an aerobic bacteria which requires an adequate flow of oxygen and nitrite to prosper. Most often, these bacteria are cultured in filters which provide the clean hard surfaces they need to attach to. The nutrients provided by the water as it flows through the media are normally suitable to produce enough of a population to remove all the nitrite in the aquarium as soon as it is produced. Always rinse your media with the aquarium water when you do the 25% change every two weeks. Never use fresh chlorinated water from the tap.

One problem that nitrobacter have always had is that they are inhibited by the presence of ammonia in the water solution. This means that nitrobacter cannot become active in the new aquarium until the population of nitrosomonas bacteria has thrived enough to remove all ammonia as soon as it is produced. Until this does occur, the nitrite in the aquarium will simply rise in concentration while ammonia is still evident.

Adding new animal life to the established aquarium....

New Tank Syndrome,

Cycling a Aquarium by: Brian Warner


One of the hardest things in keeping a aquarium is establishing a good biological filter to break down the ammonia and nitrite in your aquarium into nitrate. Unfortunately this is the first step to creating a happy, healthy and beautiful aquarium that we all strive for. Countless people have given up shortly after trying to keep an aquarium simply because of all of the headaches and hassles when trying to get past the 1st 6-8 weeks while the biological filter is established. Even an experienced fish keeper will often have problems with poor water conditions, disease, and death during these all-important two months. Throughout the course of this article and in some upcoming articles I will be talking a close up look at the process that is commonly referred to as "cycling" or establishing the necessary bacteria to break down these toxic waste all fish put out into less toxic substances. By the time you are done reading this you will have a much better understanding of what exactly is going on in your aquarium during this time, why the water gets cloudy and can turn into the color of pea soup.

Step 1 Ammonia:

Ammonia is produced by several means in your aquarium and is the most toxic of the substances that is found in a newly setup aquarium. Sources of ammonia in a aquarium are from two main sources, the fish themselves and the decomposing of uneaten food and dead plants. Fish will start to show signs of stress when very small amounts of ammonia are present in your aquarium water, less then one part per million (ppm). At higher levels the ammonia will start to inflame the gills of the fish causing them problems breathing make them much more susceptible to other diseases that they could normally fight off.

In a new aquarium there is no means for the ammonia to be removed and it will quickly build up to toxic levels, but fortunately nature has a solution for this problem and that is Nitrosomonas bacteria, which will break down the ammonia into less toxic nitrite. In a new aquarium these isn't any of these bacteria present and the first step is to get these bacteria into the aquarium. These bacteria are found everywhere in nature and in the air and will find their way into your aquarium and once there they need certain things to grow namely oxygen rich water and ammonia as food. They also need a surface to attach to for them to grow in sufficient numbers to handle the amounts of ammonia produced in an aquarium. Your first job is to provide them with this type of environment and give them time to get established. The fish provide them with the ammonia, and you provide them with the oxygen rich water, and a good surface to live on in your filter. Adding some sand from an established tank will help, also a few expendable fish.

It takes time for enough of these Nitrosomonas bacteria to get established in your aquarium, and until they do you will see certain affects to your water. Now once these bacteria get into your aquarium they don't immediately attach themselves to a surface and you will experience a bacteria bloom in your water that will turn your aquarium water a milky white color. This is caused by the large numbers of the bacteria free floating in the water feeding on the excess ammonia in your water. The second problem often caused by increased ammonia levels is an algae bloom. Like most plants algae can take ammonia directly out of your aquarium water and use it as food. This creates a bad environment for your fish but a very good environment for algae to grow and will cause your water to turn a nice green color. This is when most people who are new to keeping fish become upset, their nice new aquarium that they so looked forward to admiring has now become a green eye sore. The best thing to do here is just wait it out. Partial water changes can help reduced the ammonia levels and the amount of algae but the problem won't truly go away until enough of the Nitrosomonas bacteria have established themselves to keep the ammonia levels down. Once enough of these bacteria have established themselves in your biological filter surface you can expect to see the combination of either cloudy or green water fade away as the high ammonia levels drop off, with the algae usually taking a little longer to fade.

Step 2 Nitrite:

Well, now you have enough Nitrosomonas bacteria established in your aquarium, and the ammonia levels have dropped off to undetectable on your ammonia test kit, and the water has finally cleared you are feeling very happy about your new aquarium and start admiring it again. But now come round number two, the build up of nitrite in your aquarium. Now unlike ammonia which comes from several sources nitrite only comes directly from the breaking down of ammonia by your biological filter, and is much less toxic to your fish then ammonia. Now you are in need of yet another type of bacteria in your biological filter, Nitrobacter bacteria. These new bacteria will finally break down the nitrite into the much less toxic nitrate that will be removed by your bi-weekly water changes.

Once again though you will have elevated levels of a substance that algae can use directly for food so you could experience yet another algae bloom and another bacterial bloom of these Nitrobacter bacteria. The same process as used for the ammonia spike will also work for the affects of the nitrite spike. Small partial water changes as necessary to maintain the health of the fish, and to wait out the cloudy and algae colored water. Now it is very important to not add any addition fish at this point of the cycling. This will increase the amount of ammonia being produced in the tank and until the Nitrosomonas bacteria adjust to that level there will be a slight increase amount of ammonia in your water. This becomes a problem in that the Nitrobacter bacteria are stunted by increase ammonia levels and can increase the length of time that it takes for enough of the Nitrobacter bacteria to be established.

Step 3 Nitrate and keeping it going:

We now come to the last and finial steps in the establishment of a healthy biological filter in your aquarium and that is rising levels of nitrate. Once you start seeing positive test for nitrate and show no or only trace amounts of both ammonia and nitrite you now have enough of the two types of nitrify bacteria present to handle the current fish load. There isn't a bacterial natural process that normally occurs in an aquarium that will reduce the amount of nitrate in your aquarium. Adding some sand from an established tank will help it, and water changes also will reduce the amounts (25% every two week or whenever test show it is needed.) If nitrates are not kept down you will once again see another algae bloom because of all of the nitrate in the water that the algae will use for food.

Now that you have your biological filter established you need to take care that it doesn't die off just like you do for every other living things in your aquarium. You should give it as much consideration as you do the other living things in your aquarium, the fish and plants.

Take care when doing maintenance on your filter not to kill off or remove too many of these bacteria that you have worked so hard to get established there. Also take care and don't try to increase your fish load too quickly.

Every time you add new fish and as fish grow it takes some time for the biological filter to adjust to the new conditions and most of the time it will do so without any problems.

What you want to avoid is suddenly dumping in twice as many fish as you already have in a lightly stocked aquarium and expect that since you have already cycled your aquarium you won't have any problems. While you won't see near the levels of ammonia and nitrate that you did while cycling it is common to see slightly increase levels. Also you will find that for about the first month or so after completing the initial cycle your biological filter will be particularly venerable to sudden changes in the fish load.

After that first month after the cycle the aquarium is really pretty stable and as long as you keep up with your aquarium maintenance you should find that finally your aquarium has become what you first envisioned it to be a very beautiful and healthy addition to your house. Now is the time that you will really start to see why this hobby can become so very addicting and so many people start to feel the need to setup more and more aquariums.

What is the Nitrogen Cycle?

The nitrogen cycle is the process by which toxic ammonia (NH3) is converted into nitrites (NO2-), and then into nitrates (NO3-) by the production of beneficial bacteria. In aquatic systems, especially captive environments, the nitrogen cycle must be allowed to complete before inhabitants are introduced; this is referred to as cycling the tank. Once the nitrogen cycle has been established in a new tank, it is a continuous conversion process (hence the word cycle in nitrogen cycle). Because captive environments are typically very tiny compared to natural habitats, this biological cycle will at some point require some assistance in the form of tank maintenance (i.e. gravel vacuuming, water changes, filter changes etc.).


AQUAPAGES Aquarium Doctor

In this part of the website, you will also find out how to take care of algae problems, what to feed your fish, what the proper water parameters are, and many other good techniques to keeping your fish and invertebrate happy and healthy. With this information, members will have a much better understanding of keeping their tank in top condition.



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