Knowing how to cycle your fish tank is very important for new aquarium owners. You will need to wait at least 4-6 weeks for your new aquarium to fully cycle because the filter needs sufficient time to colonize all of the beneficial bacteria. It can be really difficult to understand how this process all works, especially if you are a beginner. Make sure to do your research. I cannot stress enough just how important it is to cycle your tank before stocking it with fish. I have to agree, cycling your tank requires much patience but it is better to do it properly than to risk the life of your livestock.
Every aquarium needs a cycled filter whether it be internal or external. I highly recommend the Fluval U Series range, especially for beginners.
Believe it or not, fish are not safe to be added into a new aquarium after 24 hours or even a few days. Anybody that tells you this has no idea what they are talking about. You cannot add fish into a uncycled aquarium. Every aquarium needs a cycled filter. A cycled filter should be keeping ammonia and nitrite levels to 0ppm (parts per million) which is perfect for fish to thrive in. Without a cycled filter, harmful toxins soon build up in the water and cause illness to the fish which often result in death. This is one of the reasons people cannot understand how quickly their fish has got sick and died after bringing them home. It is also why some give up the hobby before it has even started.
A simple diagram explaining the nitrogen cycle. The nitrogen cycle is a process where beneficial bacteria becomes established in your tank and filter media, allowing ammonia to convert to nitrite and then nitrite to nitrates.
So how does this cycling process work? I will try and keep things as simple as possible. Your fish produces waste which gets released into the water. This is called ammonia. Ammonia will continue to build up until the bacteria that eats it starts to form which is called nitrite. Your tank may become cloudy when this bacteria starts to form. It is often referred to as a bacterial bloom. Without the nitrogen cycle, your fish will be killed by it's own waste. I can think of much nicer ways to die which is why the nitrogen cycle is needed. The nitrogen cycle is a process where beneficial bacteria becomes established in your tank and filter media, allowing ammonia to convert to nitrite and then nitrite to nitrates. Remember, nitrate isn't toxic in small amounts but ammonia and nitrite is very toxic even in small amounts. Nitrate is the final product of the nitrogen cycle and can be removed by doing regular water changes. The next article discusses this in more depth.
Danios are incredibly hardy and tolerate a wide range of temperature and water chemistry, making them excellent fish for beginners and newly set up aquariums.
Now that you know this, what's the best way to start the cycling process? There are a few different methods but I will talk about two of the most popular methods. In the first few weeks of having your new aquarium set up and assuming you have already added your substrate, water and have the filtration system set up...the best thing you can do is add a few live plants into the environment. A few small ‘hardy cycling fish’ such as minnows or danios will also be helpful to the process. Your aim is to populate the tank with fish that produce waste but can also survive the high levels of ammonia and nitrite long enough to allow for the beneficial bacteria to grow. While you're waiting for your tank to cycle, make sure to replace approximately 25% of the tank's water every few days, to ensure toxic levels of waste (ammonia and nitrite) do not build up and kill your 'hardy cycling fish' before the tank is fully cycled. If scores of ammonia and nitrite are coming up extremely high, make sure to do a 50% water change. I will recommend to any fishkeeper to invest in a bottle of Seachem Prime which converts ammonia into a safe, non-toxic form that is readily removed by the tank's biofilter. Prime may also be used during tank cycling to alleviate ammonia and nitrite toxicity. Prime detoxifies nitrite and nitrate, allowing the biofilter to more efficiently remove them. If you have a saltwater tank, remember to add marine salts to maintain proper salinity. It is also very important for fishkeepers to invest in a good quality water testing kit so you can keep a regular check on water parameters. You can purchase these at almost any aquatic store and they are a must-have when fishkeeping.
It is very important to invest in a good quality water testing kit when you purchase your first aquarium. Try and avoid the strip tests as they often provide inaccurate results.
Another method some people use is adding their own bacteria to the water. This is called a fishless cycle. Some people will add bottled ammonia to the aquarium water. Aquatic stores also sell bottled solutions of beneficial bacteria that can help with the process of cycling. If you want to do a cycle which doesn't involve fish then I would recommend using Fluval Cycle which contains beneficial bacteria and is to be dosed daily or Prodibio Start Up vials which are very easy to use. Make sure to read all instructions before use. The scores from your water testing kit will be able to give you an approximate idea of where you are in the cycling process. It can take a while to get results doing a fishless cycle, so stick with it. When the filter has cycled, you should have scores of 0ppm ammonia, 0ppm nitrite and at least 5ppm nitrate or above. This means your filter is doing the job it is meant for, is cycled and you can gradually add fish to the aquarium. The golden rule is not to overload the tank with too many fish at once. After you add a new fish, wait another week and test the water again to ensure the ammonia and nitrite levels are still low before you introduce another fish. The last thing you want to do is overwhelm the filter beyond what it can cope with. Cycling your tank can be a long process but it is definitely worth the wait when you can finally stock it with fish. That is when the real fun begins as the next article discusses.