Making sure your tank is cycled is crucial if you want to maintain a healthy environment in your fish tank. But how do you know if your tank is cycled?
In general, the best way to know if your fish tank is properly cycled is by using a test kit. You’ll want to test your tank water and ensure there are 0 ammonia, 0 nitrites, and 30-40 ppm of nitrates. This is a good sign your tank is cycled properly, and you can introduce fish into your aquarium.
Using a test kit, in my opinion, is the most accurate way to know if your fish tank has completed the nitrogen cycle.
I recommend using the API Freshwater Master Test Kit. Check prices on Amazon Here.
You can use test strips as well, but you’ll most likely have to buy an ammonia test strip tester and a nitrite/nitrate test strip tester. Not to mention, these test strips are usually good for around 20 tests.
In the long run, the API kit is the best bang for your buck, in my opinion.
Now, let’s talk about some other signs you can look for in a cycled aquarium, the different ways to cycle your fish tank, and how you can speed up the process.
What Are The Signs Of A Cycled Aquarium
Everyone has their own preferred method of creating a cycled aquarium. Some like to use a fish-in cycle, while others are completely against that and prefer a fishless cycle. (both of these methods will be discussed later on)
However, the more advanced fishkeepers will probably use an instant cycle method on a new fish tank.
But what are the signs you should look for to know that your fish tank cycle has been completed?
The most common signs to look for in freshwater aquariums are:
- Thriving Fish: your fish is one of the best indicators of how well your fish tank is set up. A good sign is to see them actively swimming around and eating.
- Plant and Algae Growth: This is another good indicator that your aquarium cycle is headed in the right direction.
These are the two good indicators to see if your fish tank cycle is headed in the right direction.
But the best indicator of all…
Best Indicator When The Nitrogen Cycle Is Complete
There is honestly no replacement for testing your water parameters with a test kit. You can not see the ammonia produced in the water without testing. This is the same for nitrite and nitrate levels.
Yes, the signs listed above can be good indicators. But it’s not certain. The only certainty you can have is by actually testing your water quality.
So why is testing the best indicator that your nitrogen cycle is complete?
You see…
The nitrogen cycle consists of three phases…
Ammonia -> Nitrite -> Nitrate
You want to see a spike in ammonia levels. Ammonia is what jumpstart the entire process. Without ammonia, there is no cycling process that can start.
So, you want to test to ensure there is ammonia produced in the water column. (I’ll go over how to get ammonia levels in your fish tank later in this article)
After a spike in ammonia levels, you should notice a drop in ammonia and nitrite levels starting to spike.
This is a good sign that the beneficial bacteria in your tank are at work.
When the nitrogen cycle is completed, you should see 0 ammonia levels and 0 nitrites and see your nitrates start to spike. (1)
This is the best indicator that your beneficial bacterial colonies have established tank in the tank, and your aquarium cycle is most likely completed.
But remember, your cycling process is an ecosystem. The nitrifying bacterial colonies only grow to as much ammonia as there was during the cycling process.
So, if you suddenly increase the amount of fish in your tank or disrupt your filter media, you can crash your cycled tank.
Now, let’s talk about the different ways to cycle your aquarium.
What Are The Different Ways To Cycle An Aquarium
Below are 2 of the most popular ways to cycle your fish tank. But no matter which method you use, keep in mind you will always need a source of ammonia in order to jumpstart the cycling process and also a way to introduce beneficial bacteria into your fish tank.
My recommended product to introduce beneficial bacteria is Seachem Stability. You can check prices on Amazon here.
This can be used with both the fish in the cycling process and the fish-less method.
Now, let’s go over each of these methods…
Fish In Cycling Method
This is an old-school method that uses fish to start the cycling process within your fish tank.
Some fishkeepers frown upon this method because of how cruel it can be to the fish.
However, with the rise of recent products that can detoxify ammonia, nitrite, and nitrates and introduce beneficial bacteria quickly. There is debate that this method isn’t as cruel as it used to be.
What you’ll want to do is treat your water with a water conditioner that dechlorinates your tap water, making it safe for fish.
Then, you will set up your aquarium and add a few fish into the tank (at this point, you will want to continue to dose Seachem prime and stability daily for the first seven days as recommended).
Now, as you add fish food, these fish will start pooping and peeing in your fish tank. This waste that they produce will create ammonia within your tank.
Fish Waste And Fish Food
This is what will fuel the source of ammonia within your tank, and this is what will feed the nitrifying bacteria in order to start the nitrogen cycle.
Again, remember you’ll want to continue to dose Seachem Prime and Stability in order to keep your fish safe from the harmful bacteria and chemicals being produced.
Then, test your water until you have reached 0 ammonia levels and 0 nitrite levels, and your nitrate levels start to spike.
This is a good sign your tank is cycled. But you’ll still want to continue to test weekly and ensure there is no cycle crash or your nitrates are not getting to dangerous levels (if they are, then it’ll be time for a water change).
Now, let’s talk about another way to complete the cycling process.
Fish Less Cycling Process
With this method, you won’t be introducing any fish until your tank is cycled.
But you are still going to need a source of ammonia to start the nitrogen cycle…
Some people may recommend “ghost feeding” your aquarium with fish food. The uneaten fish food will decompose and start to produce ammonia.
However, this can be a slow process and may not produce enough ammonia to create a good amount of beneficial bacteria.
Instead, I recommend using an external ammonia source…
External Ammonia Source
I recommend using Dr. Tim’s Ammonium Chloride Solution for fishless cycling. You can check the prices on Amazon here.
You’ll want to dose this ammonia source as well as use Seachem Stability in order to introduce beneficial bacteria into your fish tank.
The idea is to keep dosing ammonia into your fish tank daily to maintain a source of ammonia for the beneficial bacteria to grow and multiply.
Keep doing this daily until you are able to test 0 ammonia and 0 nitrite with nitrate levels present.
Now, let’s talk about how to speed up the process and create an “instant cycled tank.”
Can You Speed Up The Process
Yes, you can speed up the cycling process. But, in order to do so, you will either need an already established fish tank that’s been properly cycled or a friend with an established aquarium.
In order to speed up the process and create an “instant cycled tank,” as some aquarists call it, you will need to use filter media and substrate from a fish tank that’s already been through the cycling process.
Use Established Aquarium Filter Media And Substrate
When you use established filter media and substrate from a fish tank that’s been properly cycled, you’ll already have a build-up of beneficial bacteria that are ready for the nitrogen cycle and will help with biological filtration.
This is one of the fastest ways to cycle a new fish tank.
I personally still like to use Seachem Prime and Stability as a safety net for the first few days. But this is just personal preference and peace of mind for myself…
You still will want to introduce a few more fish slowly into this aquarium. Keep an eye on water quality and water parameters to make sure everything is in order.
Do You Really Need To Cycle An Aquarium
Every fish tank should be properly cycled if you want to create a healthy environment for your fish and other livestock to live in.
You can read this post on what happens if you don’t cycle your fish tank to learn more about what might happen.
But if you don’t have an aquarium cycle established, only bad things can come from it…
Does Algae Mean My Fish Tank Is Cycled
There are many signs that fishkeepers can use to understand the condition of their aquarium…
Plant growth and algae growth are good signs that your fish tank is headed in the right direction. However, algae growth alone is not enough information to know if your tank cycled properly. You will want to test water parameters with a test kit in order to know for sure.
How To Know If A Tank Is Cycled Without A Test Kit
As you probably know by now. I do not recommend relying on “signs” in order to see if your aquarium cycle is complete.
I want to be clear that testing your aquarium tank water is the most accurate way to see if your tank has been cycled properly.
But if you choose to rely on signs. Here are the things I would look for…
Fish Are Alive
One of the biggest signs your aquarium cycle is doing well is that your fish are alive. Ammonia is highly toxic to fish, and ammonia poisoning can lead to death.
If your fish are thriving, alive, and well, this is a good sign to see within your aquarium.
But you also want to make sure your fish are not just alive, but also…
Your Fish Are Active And Eating
Another good sign to see is your fish are active within your tank and eating regularly.
Ammonia is highly toxic to fish, and ammonia poisoning can lead to lethargic fish.
You may notice some unusual behavior as your fish stay in the corners of your tank, either on the bottom or top of your aquarium.
They may stop eating or have no interest in food at all.
You also may notice rapid breathing in your fish.
These are common symptoms of highly toxic levels of ammonia and nitrite.
But it’s a good sign if your fish is active, eating, and swimming around within your tank.
Plants Are Growing And Signs Of Algae Growth
Another good sign to see is plants and algae growing within your fish tank. This is a good indicator that your fish tank cycle is headed in the right direction.
But remember, it can never replace actually testing your tank water.
Final Thoughts On The Signs Of A Cycled Aquarium
Now, you should know the signs to look for if your fish tank is cycled properly.
My number one recommended method is to test your aquarium’s water with a testing kit.
This is the surefire way to know whether or not the beneficial bacteria within your tank are completing the nitrogen cycle.
The other signs are good guide posts, but you will never truly know the true metrics if you are just relying on those signs alone.
I hope I was able to answer any questions you have about this topic. Thank you again for being here on my blog, and a special thank you to you if you made it all the way down here to read this!
I wish you the best in your fishkeeping journey, and I hope to see you in another post!