The novice aquarist must face a variety of problems when a new tank is started. Beginning aquarium woes often commence with the lack of understanding exactly what is going to happen in the first six weeks the tank is active. Without knowing what processes are occurring invisibly in the aquarium, too many beginners overload the aquarium with fish right away and sentence their new pets to death by their own excretions. The fish actually create the majority of the poisons that kill them!
Often the rest of the deadly compounds comes from excessive feeding that rots and promotes decay. In the new aquarium, Ammonia is produced by the fish and decay processes. It can rapidly build to toxic levels. If the pH is acid (below 7.0) the toxicity of ammonia is often minimal, even in what could be considered high concentrations. However, it rapidly becomes extremely deadly when the pH reading rises over 7.0. The higher the pH, the more dangerous ammonia becomes, even in smaller concentrations.
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| Nitrogen Cycle in aquariums. Legend: (1) Addition of food and nutrients, (2) Production of Urea and Ammonia by Fish, (3) Ammonia is converted to Nitrites by beneficial Nitrosomonas bacteria, (4) Nitrites are converted to Nitrates by beneficial Nitrospira bacteria. Less toxic Nitrates are removed by plants and periodic water changes. (5) Evaporation. (6) Light, (7) Soil, (8) O 2 produced by plants, (9) CO 2 produced by Fish (Photo credit: Wikipedia) |
As time goes by, even starting from a sterile environment, beneficial bacteria that specialize in using the ammonia as an energy source establish a foothold. With enough time, adequate populations develop that can reduce the ammonia as quickly as it is produced. They produce nitrite as a by-product. Nitrite has no relationship with pH or any other water characteristic. As nitrite rises in concentration, it is equally deadly for fish in any water conditions. Once again, nature has provided a bacterial strain that will rapidly eliminate nitrite, nitrobacter. The specialized bacterial strains use nitrite for energy and create nitrate as the final step.
Nitrate is a good plant fertilizer, but otherwise is not removed by standard processes in the aquarium. It constantly builds to levels that eventually become harmful to fish. There really is no reliable way to remove it other than by dilution. The standard water change is the most effective method to remove high levels of nitrate with the waste water. Fresh tap replacement water replacement normally has low or non-existent amounts. As new water is added to replace siphoned used aquarium water, the overall levels of nitrate are lowered and controlled by this simple method.
The entire system heavily depends on a strong and vibrant population of two separate bacterial strains (nitrosomonas and nitrobacter) doing their job. In addition there are a multitude of other bacteria that are constantly at work breaking down waste materials into component parts this is the natural decay process. A big part of this waste removal is the production of ammonia. In the very beginning, there are no bacteria of any kind to start with, they have been killed by the chemicals water companies put into the water supply to make it safe for human consumption. Assorted bacteria strains do start to populate quite quickly, but as far as the invisible bacterial world is concerned, ammonia and nitrite reducers are quite slow to replicate. There are many other types that are much faster to exploit a suitable niche and can inhibit nitrosomonas and/or nitrobacter from thriving.
It takes ten days in a perfect environment for a single starting bacteria that reduces ammonia to populate the billions upon billions of its fellows required to eliminate ammonia as soon as it occurs. The bacteria that reduces nitrite to nitrate is even slower to replicate. It has the further disadvantage of being inhibited when there is too much ammonia present. Once the ammonia removing bacteria are plentiful enough to eliminate ammonia immediately, then these weaker strains will begin to grow, taking another three weeks to get to high enough densities to remove nitrite immediately as well.
Biological Augmentation of the bacterial filter
The above is a very brief synopsis of the Nitrogen Cycle, it is meant neither to be complete or exhaustive, but the timing of the bacterial population crests are important. It is this long lag behind many other types of bacteria all fighting for the same space and elements that gave rise to the concept of bacterial augmentation of the biological filter. Although there are disagreements of which particular strain of bacteria that actually do the work removing ammonia, classically it has been defined as nitrosomonas, and few would argue that these are the bacteria that can do the work. In the past few decades, certified pure strains of both nitrosomonas and nitrobacter have been isolated and cultured quite successfully. Even before this advance, it was long felt that if you added these bacteria to the aquarium directly, they would help reduce the length it takes to get the populations up to size as well as keep the actual concentration levels much lower.
In the very early days, this was done by simply grabbing a handful of gravel from an old, established aquarium and adding it directly into the new aquarium. Since both of these previously mentioned beneficial bacteria are lithotrophic and attach firmly to clean hard surfaces, this did work to inoculate a beginning aquarium with the bacteria living in the old tank, whatever the strains. There was always the risk that the older tank had other, less desirable strains that tagged along as well. Many tanks introduced a disease into it along with the beneficial bacteria.
Then came the first bacterial suspensions that contained living bacteria, in the early 1980's. These were actual living and breathing bacteria, bottled active and alive and sold with very short expiration dates. The concept was to provide a concentration of specifically cultured bacteria that do a particular job and supercharge a new system with them. The spikes of ammonia and nitrite were felt to be reduced and the fish had a better chance of surviving the break-in ordeal. The main drawback of this first product was that it went out of date so fast. You had to get it right off the truck and use it immediately, as every hour saw the loss of some more of the bacteria.
Soon a newer product arrived that was able to deliver much higher concentrations of both bacteria, coupled with some of the best waste reduction bacteria in the same bottle. The shelf life, from culture vat to consumer was extended because it exploited the newest technology, which allowed pure cultures of nitrosomonas and nitrobacter along with a few powerful waste reduction strains to be cultured into extremely high concentrations and then shut down and forced to hibernate until the bottle was opened. The advancement of causing the dormancy of the bacteria was thought to be impossible, and although many seem to believe it still can't be done, the success of the product for over 20 years on the market proves it to be viable.
When the technology advanced to the point where billions of bacteria spores and hibernating cells were concentrated into every ounce, the concept of competitive exclusion also became a reality. Unlike throwing a handful of gravel into a new tank and hoping the right bacteria strains make it, the ability to culture a pure strain of bacteria, mix it with other pure strains to form a team allows the knowledge of exactly what is being put into the aquarium. By dosing in recommended amounts every week, the balance of population is shifted in favor of the strains being added. Over time, they become the dominant bacterial strains, which is fine, because if other pathogenic species appear, they are crowded out by the more dominant types. This is the definition of competitive exclusion, inoculating the aquarium with the beneficial bacteria and crowding out potential pathogens.
Many companies have provided products like this to the market, have a friendly chat with your local life fish store about which one of these preparations they recommend. By regularly dosing the filter and aquarium with billions of bacteria every week, the tank stays in better health and actually seems to run with less chance of bacterial disease. Fungus is also reduced as the amount of waste is more rapidly decayed to composite parts before a problem can occur.
Having kept and bred many different types of tropical fish for the past forty years, I am dedicated to providing information required for the novice aquarist to become successful in this fascinating hobby. Keep tropical fish alive and thriving in your first aquarium through the critical first six week and beyond. Visit my blog website (http://www.noviceaquarist.com/blog) for more detailed information specifically tailored for the novice aquarist on all aspects of the beginning aquarium. Besides my own personal contributions, a variety of other sources are polled and added regularly to the content warehouse available there. Article Directory: EzineArticles |
