How Long To Quarantine New Fish Before Adding To Tank

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Written By Fun Fish Tanks

I Love my Fishes 

Bringing new fish into an aquarium can be an exciting experience, but it’s important to remember that introducing new fish can also pose a risk to the existing aquatic community.

Fish that appear healthy and disease-free may carry harmful pathogens that can quickly spread to other fish, leading to illness and even death.

Quarantining new fish is a crucial step in maintaining a healthy aquarium and preventing the spread of disease. But how long should new fish be quarantined?

In this article, we’ll explore the factors that influence the duration of a fish quarantine and provide tips on how to properly quarantine new fish to ensure the long-term health of your aquarium. 

Why Should I Quarantine My New Fish? 

Adding new fish to your aquarium can be an exciting experience, but it’s important to remember that new fish can carry diseases that can quickly spread to the existing aquatic community.

Quarantining new fish is a crucial step in maintaining a healthy aquarium and preventing the spread of disease. 

There are chances that you can introduce a disease or parasite-ridden fish into your tank. Even if it is from a high-quality breeding environment, some fish can carry diseases.

So, quarantining them is important because it will prevent the disease or parasite from getting into your perfect aquarium. 

If you don’t quarantine a new fish before adding it to your tank, then if the new fish is disease borne then your aquarium will get contaminated. Your aquatic pets will fall prey to diseases and if not treated can die.

How long to quarantine new fish before adding to your fish tank?

When introducing new fish to your aquarium, it’s important to quarantine them first to prevent the spread of disease.

Therefore, a quarantine period of 2 to 4 weeks is recommended for new fish. During this time, the new fish should be closely monitored for any signs of illness, such as lethargy, loss of appetite, or abnormal behavior.

Although, the duration of a quarantine period can vary depending on the individual situation. Factors such as the health of the new fish, the type of fish, and the size of the quarantine tank can all influence the duration of the quarantine period.

It’s important to closely monitor new fish for any signs of illness and to adjust the duration of the quarantine period as necessary.

By taking the time to properly quarantine new fish, you can help prevent the spread of disease and ensure the long-term health of your aquatic community.

What Items Will I Need for a Fish Quarantine? 

The are several essential items that you need for quarantining fish. Quarantining is necessary to avoid diseases form entering your aquarium, therefore, you have to gather some pieces of equipment for quarantining fish. The pieces of equipment required are as follows: 

  • Separate tank
  • Filter
  • Heater
  • Thermometer
  • Air pump 
  • Airstone 
  • Net
  • Sponge filter 
  • Water Testing Kit
  • Dechlorinator

In addition to these essential items, it’s important to have a separate set of cleaning equipment, such as buckets and siphons, to avoid cross-contamination between the quarantine tank and the main tank. 

How to Set Up a Quarantine Fish Tank? 

As quarantining fish comes as a crucial step in the maintenance of a healthy aquarium, you must know how to set up a quarantine tank. Here’s how to set up a quarantine fish tank: 

  • Get the correct tank according to the size of the fish you have to quarantine. Also assemble the required equipment such as heater and filter. 
  • When it comes to getting started setting up the aquarium you need to start with the tank itself. Whether you chose a tank that is all glass or acrylic you want to be sure that you prepare it first. You cannot simply pull the tank out of the box and start filling it with water.
  • There is likely going to be some type of residue on the surfaces inside the aquarium. Be sure to thoroughly wash all of the surfaces inside the tank and then rinse it.
  • Be sure to rinse it completely to ensure that the fish do not get exposed to any amount of soap. 
  • Next step is to fill the tank and add a dechlorinator to get rid of the chlorine. 
  • Now you have to set up the filter and heater in the tank.
  • You can add decors according to your wish or the preference of the species of fish you have. A substrate is not necessary and it will easier for you to clean the tank as well. 
  • Then followed by the adjustment of water parameters. You have to replicate the water parameters of the main tank. Although with temperature you can raise it a bit as it helps the fish in fighting diseases. 
  • Lastly, you have to add the fish in the quarantine tank. You can use a fish net to gently move the fishes to a new tank.
  • Then you have to observe the fish for signs of diseases and be ready with treatments.
  • Lastly, you will need to use the water testing kit to regularly check the water conditions of your Quarantine tank.

How big does a quarantine tank need to be? 

When it comes to the size of the quarantine tank, it solely depends on the size of the fish that you have to quarantine. But even so, the average size of tank you should go for is 20 to 30 gallons.

But make sure not to go for a tank less than 10 gallons in size. However, if you plan to quarantine larger fish or a large number of fish, a bigger tank may be necessary.

How do You Keep a Quarantine Tank Cycled? 

In addition to setting it up and adding fish, an important procedure is to keep the quarantine tank cycled. For a tank to have a nitrogen cycle is an absolute necessity and you must set a cycle in your quarantine tank. 

For this, you can use the sponge filter media from your main tank in the filter of the quarantine tank.

Also if you have a sponge filter you can run the filter in the quarantine tank. You can do this every time you need to quarantine a fish before adding it to your aquarium or other times. 

Using the sponge filter media or running the sponge filter from the main tank will release beneficial bacteria into the quarantine tank. This is enough to start the cycle in your quarantine tank.

After the quarantine is over, you can add the filter media or the filter back to your main tank.

Can I quarantine fish in a bucket? 

Even though a proper aquarium is recommended for quarantining fish, if you don’t have another tank with you then you can use a bucket.

But the bucket or any container has to be completely safe for the fishes and it must be big and large enough for the fish to swim around. 

Also, it will be better to use a container that has transparent size. With this it will be easier for you to observe the fish and its behaviours.

Do I have to quarantine my first fish? 

If it’s the first time that you are keeping fish, then it is not necessary to quarantine the fish. As there will be no other fishes present in the aquarium that needs protection from diseases. Also, you can treat your first fish in your main tank itself. 

But if you have a large tank, then you can go for a quarantine setup. As it is easier and budget friendly to treat and dose medicine in a smaller tank rather than a large one. 

Also, if you have plants and other aquatic creatures such as snails and shrimp present, then you have to set up a quarantine tank. The treatments you use such as salts are hard for the plants and snails to handle. Therefore, a separate quarantine tank is necessary for precaution.

What should I use to treat fish if I can’t buy the quarantine med trio? 

Sometimes it can be challenging to find the right medications to treat your fish if they get sick during the quarantine period. The quarantine med trio is a popular combination of medications used to treat bacterial, parasitic, and fungal infections in fish.

Although if you don’t have access to it where you live and you aren’t able to get it anywhere, then you must go for other forms of treatment. 

The best option to go for instead of the quarantine med trio is aquarium salts. It is a cheap and easy way to treat your fish. It is highly effective to fight against parasites, diseases, fungi, and bacteria. But make sure to follow the correct levels of dosage. 

Although make sure to use salts where there are no plants and other aquatic creatures present. Make sure to see whether the species of fish you have can handle salt or not, as it is not compatible with some species of fish.


In conclusion, quarantine is an essential step in introducing new fish to your aquarium. While the recommended quarantine period is generally two to four weeks, it’s important to observe your fish for signs of illness and adjust the quarantine period as necessary. 

As we have discussed, a proper quarantine tank setup requires several essential items, including a filter, heater, and substrate, and the tank should be cycled before introducing any fish.

In addition, it’s important to use appropriate medications to treat any illnesses that may arise during the quarantine period. By following these steps, you can help ensure the health and well-being of your fish and the overall success of your aquarium

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