The Aquarium Nitrogen Cycle
OCReef.com recommends Red Sea Nitro Bac Saltwater Bio-Starter
3.4 fl oz. bottle to help jump start your new saltwater aquarium. Continue reading article below to gain some valuable insight!
What is a Nitrogen Cycle?
Some call it the biological cycle, the nitrification process, new tank syndrome or even the start-up cycle. They're all referring to the same cycle - "The Nitrogen Cycle".
This very important cycle is the establishment of beneficial bacteria in the aquarium and in the filter media that will help in the conversion of ammonia to nitrite and then in the conversion of nitrite to nitrates. See the aquarium water chemistry chart below for a more detailed view on these terms.
The process may take 2 weeks to 2 months or longer to complete, depending on your aquarium set-up. It is vital for anyone planning on keeping aquarium fish to understand this process. Learning about this process will help you to be successful in keeping your fish friends. It will greatly improve your ability when keeping tropical fish for the first time. The best way to monitor the nitrogen cycle is to purchase an aquarium test kit that will test for ammonia, nitrites, nitrates and pH.
Begin with testing your aquarium water every other day and write down your readings. You will first see ammonia levels rising. As the days and weeks progress you'll notice the nitrite levels rising and the ammonia levels dropping. Finally, after a few weeks you should see the nitrate levels rising and the nitrite levels dropping. When you no longer can detect ammonia or nitrites, your aquarium water parameters should be nearing a safe point to start adding your aquatic friends.
Nitrogen Cycle Stages
Ammonia is introduced into the aquarium via tropical fish waste and uneaten food. The tropical fish waste and excess food will break down into either ionized ammonium (NH4) or un-ionized ammonia (NH3). Ammonium is not harmful to tropical fish but ammonia is. Whether the material turns into ammonium or ammonia depends on the pH level of the aquarium water. If the pH is under 7, you will have ammonium. If the ph is 7 or higher you will have ammonia.
Bacteria called Nitrosomonas will develop and they will oxidize the ammonia in the tank, essentially eliminating it. The by-product of ammonia oxidation is Nitrites. At this stage you no longer have ammonia in the tank, but will now have another toxin to deal with - "Nitrites". Nitrites are just as toxic to tropical fish as ammonia. If you have a test kit, you should be able to see the nitrite levels rise around the end of the first or second week.
Bacteria called Nitrobacter will develop, they will convert the nitrites into nitrates. Nitrates are not as harmful to tropical fish as ammonia or nitrites, but nitrate is still harmful in large amounts. The quickest way to rid your aquarium of nitrates is to perform partial water changes. Once your tank is well established you will need to monitor your tank water for high nitrate levels and perform partial water changes as necessary. There are other methods to control nitrates in aquariums besides water changes. For freshwater fish tanks, live aquarium plants will use up some of the nitrates. In saltwater fish tanks, live rock and deep sand beds can have anaerobic areas where denitrifying bacteria will breakdown nitrates into harmless nitrogen gas that escapes through the water surface of the aquarium.
Getting The Nitrogen Cycle Started
There are several methodologies for cycling an aquarium. Below is five recognized methods:
- Option 1: Using Fish Food Drop in a few flakes every 12 hours. As the food decomposes it will release ammonia. You will have to continue to "feed" the tank throughout the process to keep it going.
- Option 2: Use a small piece of raw fish or raw shrimp. Drop a small 1 inch piece of raw fish and/or raw shrimp into the tank. As it decomposes it will release ammonia into the tank.
- Option 3: Use gravel and/or filter media from an established and cycled tank. This is one of the best and more faster methods. This will seed the tank with all of the necessary bacteria for the nitrogen cycle. "Feed" the tank daily with flake food until you are getting nitrate readings. Depending on how fast you were able to get the gravel and filter media into your tank, you may be getting nitrate readings in only a day or two. There are some drawbacks to this method. Ask your source if they have recently used any copper medications in the tank. If they have and you are planning to have invertebrates in your saltwater tank, you should not use this method. Invertebrates will not tolerate copper. Get a copper test kit to determine if it's safe to use.
- Option 4: Use live rock when cycling your Reef or FOWLR Saltwater Tank. The use of live rock in saltwater tanks has proven successful. The reason for this is because it is one of the best forms of biological filtration available for saltwater tanks. The condition the rock is in when you get it, will determine how long the nitrogen cycle will take.
- Option 5: The are several liquid seeding bacteria's on the market to help you cycle your aquarium. Following the manufacturers instructions, when using this method.
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