Updated: Jul 26
If you do not know what the Nitrogen Cycle is, we highly recommend reading our article on the Nitrogen Cycle before reading this one. In this article, we will go through the different methods of cycling a tank, both fish-in, and fish-out.
Firstly, before you start cycling your tank, you WILL need to get a test kit to be able to test for Ammonia, Nitrite, Nitrate to be able to keep track of the progress of your cycle. We highly recommend getting an API Master Test Kit over any Test Strips as Test Strips are notoriously known to be less accurate than using a proper liquid test kit. In the long run, a test kit will save you a lot of money, especially if you’re going to be testing your water often, which is highly recommended even after your cycle is complete.
If you still would prefer to use test strips, we would recommend you get the Tetra EasyStrips or API Test Strips. Do note, however, these test strips do not test for Ammonia so you will have to get a separate Ammonia Test Strips like API Ammonia Test Strips or API Ammonia Test Kit to monitor your Ammonia Levels.
Cycling With Fish-In
While this is generally regarded as the lesser humane way of cycling a tank, this is a very common way of cycling a tank for beginners, as a lot of beginners make the mistake of buying fish without doing prior research on cycling tanks, and are forced to have to cycle the tank with their impulse purchase fish in.
1. Using bottled beneficial bacteria
This is generally the easiest and safer way to cycle a tank, at the cost of buying a bottle of live beneficial bacteria. We personally have tried Fluval Biological Enhancer and Tetra SafeStart Plus but have had the best results with Tetra SafeStart Plus. All you need to do is buy a bottle of bacteria, follow the instructions (which is usually just to add a certain dose in with the fish), and wait a week or two for your cycle to be fully complete. The fastest we’ve seen it work is around a few days. The only thing to note is that you should not do ANY water changes till about 2 weeks after adding the bacteria in, to ensure the bacteria have had time to colonize your filter, gravel and aquarium decorations. We highly recommend this method over using filter media or decorations from someone else’s established tank.
A common beginner mistake when using this method to establish one's aquarium is not having the fish in, or a source of Ammonia (which can be through Ammonia Chloride, fish food, or any other decaying matter). Without a source of ammonia or nitrite, the beneficial bacteria will die, and your cycle will not be achieved.
- All you have to do is pour in a bottle or dose of beneficial bacteria, not do water changes for a week or two and viola, cycled tank.
- You won’t risk unknowingly adding any diseases/parasites to your tank.
- Bottled bacteria may be a bit pricey to some and might not be easily available if you do not live near an aquarium store or pet store, or don’t have access to online stores like Amazon.
2. Using Filter Media, Gravel, or Decorations from An Established Tank
If you know someone or an aquarium store with an established tank, you could use part of their filter media or decorations from their tank to “seed” your tank with beneficial bacteria. Beneficial bacteria from their filter media or decorations will quickly colonize your filter media and decorations and help you establish a colony quickly. Depending on the temperature, size of your tank, and how much used material they have given you, it may take anywhere from a day to a few weeks to have a big enough colony of bacteria. Always use a source of ammonia to test if your tank is cycled before adding fish.
We do not usually recommend this method as you have no idea what kind of diseases their tank may have (that they might not even be aware of) and risk transmitting diseases or parasites to your own fish. Another risk is the media having copper in it if they have recently used any copper medication in the tank, and if you are planning on keeping invertebrates like snails or shrimps, they will not be able to tolerate copper and will most likely die. Therefore, we would always recommend going the route of a bottle of beneficial bacteria instead.
- This method speeds up the cycle A LOT.
- If you already have an established fish tank this will save you money on having to buy a bottle of bottled bacteria if you have fish-in.
- If you get used material from someone else’s established fish tank you might risk transmitting diseases or parasites to your fish.
- It might be hard to find an aquarium store or a friend that will let you take some of their used filter material, gravel or decorations.
Cycling Without Fish
To get your aquarium cycled without fish, you will need an alternative source of ammonia since you won’t be using live fish as a source. Below are some options:
1. Pure Ammonia/Ammonia Chloride
The most common and most accurate way of adding ammonia to a cycling aquarium that hobbyists use is Dr. Tim’s Ammonia Chloride. According to the instructions, you're supposed to do 4 drops per gallon of water to achieve 2ppm of Ammonia (you can do up to 5ppm of Ammonia), but most people have said that the instructions on the label are not accurate, so we would recommend using 1-2 drops per gallon, and measuring the Ammonia levels after adding in to make sure your ammonia levels are between 2-5ppm. Continue to measure Ammonia and Nitrite levels every 2 to 3 days.
Once Nitrite levels start to show, the cycle process has begun, and that indicates that bacteria that break down Ammonia into Nitrites, Nitrosomonas, have started to colonize your tank. At this point, you can dose another 2ppm of Ammonia (1-2 drop per gallon) every day or two to ensure the bacteria that breaks down Ammonia will continue to be "fed" because if you don't you're effectively starving the bacteria you're trying to grow. Once you see readings of Nitrates and a decreased reading of Nitrites, this shows that the bacteria, Nitrobacter, have begun to colonize your tank.
Once your test readings show 0ppm of Ammonia and Nitrates and a reading of >5ppm of Nitrates, your cycle is complete. To be safe, we recommend adding another dose of Dr. Tim’s Ammonia Chloride (1 drop per gallon for 2ppm of Ammonia), and if after 24 hours your test readings show 0ppm of Ammonia and Nitrates, your cycle is complete and it is safe to add fish. When tested after 24 hours, only Nitrate should be present, if your Ammonia or Nitrite levels are over 0ppm, cycling is not complete, and you should continue to cycle and test the water every 1 to 2 days until the cycle appears to be done, and then repeat the test again.
If you would like to make this process quicker, we highly recommend buying a bottle of Beneficial Bacteria such as Tetra SafeStart Plus or using used filter media, decorations or gravel from an established tank to “seed” your fish tank.
- You can accurately measure the amount of Ammonia you want to add to the tank.
- It doesn’t cloud your water or give off a weird odor.
- Ammonia/Ammonia Chloride might not be easily available to everyone.
2. Using Fish food or a Piece of Raw Fish or Raw Shrimp
This method of adding ammonia is the least effective way of adding Ammonia to your tank as the Ammonia released from the decomposition of the fish food or raw fish or shrimp might not be consistent. However, if you are not able to obtain pure Ammonia or Ammonia Chloride, you can drop a few flakes of fish food in every 12 hours, or add in a small 1-2 inch chunk of raw fish or shrimp into the tank, as the fish food or raw fish/shrimp starts to decompose, it will release Ammonia into the tank, which will “feed” the bacteria in the tank throughout the process. Continue to test and keep track of your Ammonia, Nitrite and Nitrate levels daily to ensure the Ammonia levels stay between 2-5ppm, and do not climb above 5ppm as this might kill your bacteria. Once your Ammonia and Nitrite levels are 0ppm and your Nitrate levels are above 5ppm, your cycle is complete.
- It’s the cheapest way to cycle your tank.
- Easier to get Fish Food/Raw Fish or Shrimp to cycle your tank if you Ammonia Chloride is not easily available to you.
- Your water might get cloudy and smell a little “funky”.
- If you don’t have any “seeding” material, it might take up to a month or two for the cycle to be complete as it takes time for organic material/fish food to decompose and produce ammonia.
- Doesn’t produce consistent amounts of Ammonia like a bottle of Ammonia would, and there is no exact formula for how much fish food to add to get the appropriate level of Ammonia, hence you will have to check your parameters more often to ensure there is enough Ammonia (at least 2-5ppm) in the tank to start and continue the cycle.
- Using Fish Food might trigger other types of bacteria or algae to grow (as Fish Food contains a large amount of Phosphorus which can cause increased growth of algae or algae blooms).
Key Takeaway, aka TLDR:
If you are a newbie fish-keeper and have just accidentally bought a fish without realizing that you need to cycle a tank before your fish can safely live in the tank, buy a bottle of beneficial bacteria like Tetra SafeStart Plus to save you the hassle of having to search around for someone with an established aquarium who would be willing to give you some used material, that might potentially transmit diseases or parasites to your new fish.
However, if you have not impulsively bought a new fish and would like to take the time to do a fish-less cycle before adding any fish, we would highly recommend buying a bottle of Dr. Tim’s Ammonia Chloride (and a bottle of beneficial bacteria or “seeding” material if you’d like to shorten the time for your tank to cycle) so you can accurately add Ammonia to your fish tank to kickstart the cycle. Using Ammonia Chloride provides the best results and control over the bacteria growth, and we can guarantee you will be glad you used Ammonia Chloride instead of Fish Food or a piece of dead fish/shrimp. Make sure you get a proper testing kit like the API Freshwater Master Test Kit and ensure you are keeping track of the parameters every few days to keep track of how the cycle is progressing.
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