How To Transfer Betta Fish From Cup to Tank

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by Jason Matthews



Bringing home a betta fish is exciting, but it can be a situation that goes dangerously wrong if you don’t acclimate your fish to their new tank. As betta owner enthusiasts, we’ve had lots of experience successfully transferring our bettas from their store-bought cup to a tank.

Using a water switch or drip method, you can transfer betta fish from their cup to a tank. We prefer performing a water switch since it doesn’t require any materials, but we’ll give you step-by-step instructions for both strategies.

Read on to learn how to transfer your betta fish out of their cup and the consequences of not doing so correctly. 

A Betta’s Survival Time in a Cup

betta fish in a cup

A betta fish’s survival time in a cup depends on how much water is in the cup, whether they defecate while in it, and the air temperature (which impacts the water temperature).

You should remove your betta fish from their cup as soon as possible, but not so soon that you rush the acclimation period to their new tank.

Cups are a way for new betta owners to transfer their fish from a pet store to their home. Despite the small bowls, many shops keep bettas in, such a small space is stressful and damaging to the quality of a betta’s life.

Transfer cups are even smaller, meaning oxygen will be in short supply. Furthermore, a small amount of water means the temperature can fluctuate quickly. 

Your betta will also release toxic waste when they go to the bathroom, which can build up quickly in such a small, unfiltered area.

Related article: Betta Fish 101: All you need to know

Step-by-step Guide on Transferring a Betta Fish From Cup to Tank

There are two primary ways you can help your betta fish acclimate to their new tank before removing them from their cup. Taking the time to put them through an acclimation process is crucial to prevent a shock to their system, leading to stress and death at worst. 

Option 1: Water Switch

Water switch involves gradually adding water from your tank into your betta fish’s cup over the course of 30 to 60 minutes. The process is as follows: 

  1. Ensure your tank’s water parameters meet those a betta fish requires.
  2. Dim the lights of your betta tank.
  3. Remove the lid from your betta’s transfer cup.
  4. Pour tank water (½ cup) into the transfer cup.
  5. Place the transfer cup on the tank’s water surface and let it float for 15 minutes.
  6. Add more tank water (½ cup) to the transfer cup.
  7. Repeat this process up to two more times.
  8. Use a small fish net to transfer your betta into their new home.

An alternative to this approach is to transfer your betta into a clear plastic bag, like the kind they have at the pet store. Let the bag float on top of the tank water for 15 minutes. Then, open the bag and pour a ½ cup of tank water into the bag. 

After 15 minutes, removing your betta from the bag with a net to transfer them into their new tank is safe.

Option 2: Drip Method

The water switch method is the preferred acclimation strategy for most new betta owners, given that it’s easy to do without many setup requirements. But for the sake of options, below is another acclimation method you can use.

  1. Transfer your betta fish to a larger container.
  2. Ensure they have enough water from their original cup to cover them in the new container fully.
  3. Place an airstone in with your betta fish.
  4. Create a simple siphon using an air valve and airline tubing.
  5. Place one end of the siphon into your betta’s container and the other into their tank to-be.
  6. Use the valve to allow the water from the new tank to drip into your betta’s container gradually.
  7. Once the water parameters in the container are equal to the tank, it’s safe to transfer your betta fish.
  8. Use a net to transfer your betta into their tank.
  9. Throw away the container’s water and slowly replace the lost tank volume with dechlorinated water.

Ideal Betta Tank Requirements

Whether introducing your betta fish to a brand new tank or one with fish mates, it’s crucial to ensure they have the proper water parameters to thrive.

Below are the ideal water conditions for betta fish:

  • Temperature: 75°-81°F
  • Ammonia: 0 ppm
  • Nitrite: 0 ppm
  • Nitrate: <20 ppm
  • pH: 6.5 – 7.5

Betta fish are from Thailand, so they’re accustomed to warm, tropical climates. For this reason, you should use a heater in your betta’s tank and keep a permanent thermometer in the water to ensure the temperature remains warm enough for them. 

We recommend checking your betta tank’s parameters weekly once you transfer them from their cup to their tank to ensure the water maintains these ideal conditions.

Other Considerations Before Transferring Your Betta

cups with betta fish

Betta fish are jumpers. Therefore, you should keep the lid secure on their cup or acclimation tank when adapting them to their new water environment.

However, placing a lid on your betta’s cup without holes can be deadly. That’s because oxygen diffuses into the water via the air. 

Since your betta’s cup is already in short supply of oxygen and doesn’t have a filtration system, ensuring the water’s surface has access to fresh oxygen is crucial. 

Related article: Why you have to wait 24 hours to put fish in a tank

Issues With Transfering Your Betta Without Acclimation

Even though betta fish are relatively hardy, they need time to acclimate to your tank’s water and pH to avoid getting stressed. A stressed betta fish can make them prone to conditions such as:

That’s because stress weakens a betta’s immune system, making them susceptible to getting diseases their body would normally have been able to fight.

Researchers note that while too much stress is dangerous for fish, too little stress doesn’t stimulate them enough and reduces the chances of them coping with stressful situations in the future.

But trust us when we say that stressing your betta by putting them immediately in your tank upon picking them up from the pet store isn’t beneficial. 

Since bettas have a relatively large temperature and pH parameter range, it’s still important to acclimate them to their new tank water even if their cup water and your tank’s water are similar. 

When To Consider Quarantine 

If you’ll be moving your betta fish to a brand new tank without any other tank mates, there’s no need to quarantine them. 

But if there are already other fish in the tank, it’s crucial to quarantine them for two to four weeks. Don’t keep them in their cup during this time, for it’s much too small; bettas should have a minimum of five gallons of water per fish.

The reason that it’s important to quarantine your new betta is that they could carry diseases or parasites from the pet store. So, the quarantine period will allow you to observe your betta.

If they appear healthy after two to four weeks, it’s safe to introduce them to their new tank mates.

Should you need to quarantine your betta, it’s crucial to acclimate them to their quarantine tank water using one of the two methods we shared above. Then, when you’re ready to transfer them into their forever tank home, you must once again put them through the acclimation process. 

Signs of an Unhealthy Betta Fish

Some tell-tale signs indicate whether they’re sick, whether you’re acclimating your betta fish from their cup to their quarantine or permanent tank. 

Some of the most common signs of an unhealthy betta fish include:

  • White spots
  • Clamped fins
  • Dull color
  • Lethargy
  • Sideways swimming

Never transfer a betta fish with these conditions from a cup to a tank with other fish in it. Instead, keep them in a quarantine tank and speak with your local pet store or vet about treatment.

Maintaining Your Betta’s Acclimation Transfer

How To Transfer Betta Fish From Cup to Tank

Once you transfer your betta fish from a cup to their new tank, it’s helpful to ensure you have some items in place to make their transition as stress-free as possible.

Like humans, fish have a circadian cycle that follows daylight hours. So, setting up an automatic aquarium lamp that turns on during the day and shuts off at night will help your betta fish develop a healthy sleep rhythm in their tank.

Giving your betta fish live plants is also helpful, as betta fish are native to shallow, slow-moving water with lots of vegetation.

Finally, make sure to feed your betta fish a varied diet of high-quality food. Betta fish love brine shrimp and bloodworms, which are excellent additions to betta pellets or flakes. A good diet will help strengthen your fish’s immune system, helping to prevent any transfer-related stress illnesses.

The Bottom Line

Not rushing your betta’s acclimation to their new tank is crucial for their health. 
The good news is that once they’re thriving in their new tank, they’ll offer you your own set of health benefits; according to researchers, watching live fish improves one’s mood and reduces anxiety!


Jason Matthews

My name is Jason Matthews, and welcome to my website. When other kids were bragging about how their dog could sit and roll over, I was bragging about my latest Betta Fish and the cool sea castle I just added to his aquarium. 

Jason aquariume

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