Post by Suzanah on Apr 23, 2015 3:44:09 GMT -5
The aquarium nitrogen cycle information presented below may be rather boring to most people, but it is essential to understand this process if you want to be successful at keeping fish! The nitrogen cycle is how your aquarium works. It's the very foundation of what happens in your fish tank.
Some call it the biological cycle, the nitrification process, new tank syndrome or even the start-up cycle. They all are referring to the same cycle - The Nitrogen Cycle. The aquarium nitrogen cycle is a very important process for 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 the conversion of nitrite to nitrates. The start up of a new tank or restart of an existing aquarium will be the biggest cycle your tank generally has but it will always be present.
The best way to know if your tank is ready is to test your aquarium water every other day and write down your readings. You will first see ammonia levels rising. A couple weeks or so later you should see the nitrite levels rising and the ammonia levels dropping. Finally, after a couple more weeks you should see the nitrate levels rising and the nitrite levels dropping. When you no longer detect ammonia or nitrites but you can detect nitrates you can ume that it is safe to add your tropical fish. It can take anywhere from one to two months for a tank to fully cycle.
Nitrogen Cycle Stages:
Stage 1
Ammonia is introduced into the aquarium by 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 water. If the ph is under 7, you will have ammonium. If the ph is 7 or higher you will have ammonia.
To sum up; fish poop and rotting food turn into ammonia. This is toxic to fish.
Stage 2
Soon, bacteria called nitrosomonas (positive or beneficial bacteria) will develop and they will oxidize the ammonia in the tank, essentially eliminating it. The byproduct of ammonia oxidation is Nitrites. So we no longer have ammonia in the tank, but we 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.
To sum up; positive/beneficial bacteria starts to develop and break down the ammonia into nitrites which are still toxic to fish.
Stage 3
Bacteria called nitrobacter (positive or beneficial bacteria) will develop and 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 generally once a week. Once your tank is established you will need to monitor your tank water for high nitrate levels and perform partial water changes as necessary.
To sum up; positive/beneficial bacteria converts nitrites into nitrates. In low levels nitrates are fine but if they get high they're still not good for your fish. This is why water changes are needed on a regular basis. The filter won't take nitrates out.
There is another method to control nitrates in aquariums besides water changes. For freshwater fish tanks, live aquarium plants will use up some of the nitrates. Live water plants are awesome in helping with the nitrogen cycle and help keep the water crystal clear.
Cycling with fish in is possible but a major pain and will take careful watching and a ton of water changes. I wouldn't particularly recommend it unless you have experience. I've done it - it's a pain in the butt. The tank will be prone to major spikes in levels when doing this. You can also experience levels of both ammonia and nitrites at the same time.
Changing the water will remove a negledgable portion of the good bacteria growing in your tank as it grows mainly in your filter and on any hard surface in your tank - décor, rocks, plants etc. 60% to 90% of your positive/beneficial bacteria lives in your filter depending on how much décor, substrate, and type of filter you have.
It can be confusing so here are some images or check out our General Aquarium Care Web Links for videos and more information on the nitrogen cycle and getting your tank ready for fish.
It can be confusing so here are some images or check out our General Aquarium Care Web Links for videos and more information on the nitrogen cycle and getting your tank ready for fish.
(Images courtesy of google)
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