The Nitrogen Cycle
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[edit] What is the Nitrogen Cycle?
Every new tank must under go what is known as Cycling, The Nitrogen Cycle, New Tank Syndrome, it is known many other names. During this time you must closely watch your tank and monitor the levels of Ammonia, Nitrites, and Nitrates. By monitoring these parameters you will be able to tell when your tank has become habitable for fish, or if it is still in the Cycling phase.
Cycling a tank properly is one of the hardest parts of fish keeping as you MUST refrain from fully, or partially, stocking your tank with other than the barest necessities. The conditions of the water that your tank will be going through will be dirty and cause a large amount of stress to any fish, possibly killing them. Ammonia will burn any animal both inside and out. It is essential for you to have a liquid test kit of your own to go through this process as you will using it daily. Dip or strip kits are available, but have been proven to be more inaccurate than liquid kits.
[edit] Steps of the cycle
[edit] Ammonia
The cycle is started when ammonia (NH3) is introduced into the tank (this would be by the aquatic animals if you had not triggered the cycle beforehand). This ammonia builds up until the bacteria that eat it start to form a colony (a bacteria bloom may be observed as white cloudyness within the tank), and can convert the ammonia to nitrite as fast as they are produced. When the amount of ammonia spikes, and starts to decline, you know you are going into the second phase of the cycle.
[edit] Nitrites
As your ammonia starts to decline, you will see a spike in nitrite levels. Nitrites are the byproduct of the ammonia-eating bacteria. Like the cycling in step one, you must build up enough nitrites to form a colony of bacteria that will dispose of them as they are produced. These bacteria will in turn create nitrate. Once your levels of nitrites AND ammonia have reached 0ppm ("parts per million"), your tank is said to have been cycled.
[edit] Nitrates
Nitrates are typically never fully removed. You must do partial water changes in order to keep the amount of nitrates down within acceptable ranges, above 20ppm can be just as harmful to tank inhabitants as nitrite and ammonia. A planted aquarium will use nitrates for the growth of plants, however water changes are still necessary to remove other elements like bad bacteria levels or floating particles in the water.
[edit] How to Start Your Cycle
[edit] Fishless Cycle Method
The fishless cycle is becoming very popular with aquarists because
- It is faster
- It is considered more humane
The fishless cycle consists of artificially adding ammonia to the tank instead of using fish waste straight from the animals. This can be accomplished in multiple ways, the simplest way (however slower) is to buy 1 uncooked cocktail shrimp from the grocery store and anchor it at the bottom of your tank. As this shrimp decays it will release ammonia into the water and beginning your cycle. This process can take anything from 2-6 weeks and will vary vastly from tank to tank. Daily tests on the water will help monitor the progress.
The second method to the fishless cycle would be to pour straight household liquid ammonia into the tank (can usually be found at home improvement stores etc). This method is the fastest cycling method, however it takes more attention. You will need to constantly monitor your tank’s levels to keep them at an acceptable rate.
For more details on Fishless cycling, please read this article.
[edit] Fish In Cycle Method
1-Food is given to fish. 2-Ammonia is given off. 3-Bacteria converts it to Nitrite. 4-Bacteria converts Nitrite to Nitrate. 5-Water changes carried out to reduce levels of Nitrate. 6-Sunlight enables plants to photosynthesis. 7-Bacteria in the substrate breaks down Mulm. 8-Plants give off Oxygen when lit. 9-Plants absorb Carbon dioxide during the day to grow. * Plants give off Carbon dioxide during the night.
This is the most typical way tanks are cycled, usually because it is how it is recommended to the new aquarist if they are even told about the cycling process.
This method is accomplished by simply putting fish into a new tank, their waste breaks down into ammonia and your cycle will start. This cycle can easily take 50-60 days while fishless can take much less. Frequent partial water changes will be needed (at least every 2-3 days) in order to keep the fish alive.
- Not a recommended method as the animal suffers from ammonia burns. Delicate species can often die, if not during the cycle, often shortly afterwards.
[edit] Seeding Material Cycle Method
If you already have a tank, you can use the bacteria growing in there to greatly reduce the time needed for a cycle. By simply running both filters on one tank, or placing new media in an old filter/tank. You will start to grow the needed bacteria on your new media. This can reduce the cycle time to a week or less if the media is left in the tank for an extend period. This method typically only creates a Mini-Cycle for the new tank.
- There will probably still be trace amounts of ammonia exposed to the animals. So only stock or feed very lightly and monitor levels closely as the tank is slowly stocked.
[edit] Commercial Seeding Cycle Method
There are a few products available which greatly speed up the denitrification process by providing the necessary bacteria in huge quantities in a bottle. All these product claim you can add fish from day one.
- Stability - by SeaChem claim that their product allows fish to be added immediately as long as their product is added to the tank every 24 hours for the first 7 days. It also has a organic waste bacteria in it to clear up mulm.
- BIO-Spira - MarineLand Labs also claim their product works immediately.
Cycle and other various names - Various companies. This product has came under close scrutiny in 2005 due to claims by the other companies above. It would appear this old product is based on wrong research done in the 1970s and misidentified the bacteria (Nitrobacter, Nitrosomonas) causing nitrifying in the aquarium and does not actually reduce the cycle time of your tank significantly.
- There may be trace amounts of ammonia exposed to the animals. So only stock or feed very lightly and monitor levels closely.
[edit] Hi-tech Cycle Method
Add one of the major three instantly cycling nitrifying bacteria bottles (see above) as per its instructions and dose daily for a week with a high quality water conditioner like Prime or Amquel+. The water conditioner will convert all ammonia or nitrite into a harmless form (for 24 hours) that the bacteria can still consume.
The bacteria in the bottle will instantly start to consume the ammonia or nitrite and begin to grow in population to match the tank's production of ammonia or nitrite. So in effect any leftover ammonia/nitrite caused by overstocking or overfeeding is rendered harmless.
- This method is highly recommended by the Aquarium Wiki Encyclopaedia as it rapidly renders the tank fully cycled within a few days regardless of the overstocking or overfeeding mistakes made by beginners. It is extremely unlikely to cause any harm to any aquatic pet.
