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How to Transfer a Betta Fish from Cup to Tank

Ashley Bates

By Ashley Bates

Betta fishes in cups

Betta fish are absolutely visually stunning, with flowing iridescent fins and bold coloring. It’s no wonder so many people add these gorgeous specimens to tank setups. If you have purchased a new betta fish, you may wonder how quickly you need to get them into their new home.

You may also wonder if your new betta is compatible with other fish you have. Truthfully, you might be able to have them in a multi-fish setup—but not always. So here’s what to consider before you move your betta and how to transfer when the conditions are right.


Tank Requirements for Betta Fish

  • Water pH: 6.8–7.5
  • Temperature: 75–85 degrees Fahrenheit
  • Substrate: Gravel, sand
  • Additives: Detoxifier

How Long Can a Betta Stay in the Transfer Cup?

Since your betta fish doesn’t require filtration, they should be safe in the transfer cup for a brief time. However, there are a few things to consider here.

betta fish in a cup
Image Credit: Johanna K M Nilsson, Shutterstock

There is very little water in transfer cups

Most transfer cups come with minimal water—just enough to get your betta home safely. However, these cups are in no way meant for long-term use.

Water temperature can change drastically and quickly

If your betta is in an extremely hot or cold environment, it can cause rapid temperature changes to such a small amount of water. As a result, your betta could suffer from shock.

Small transfer cups prevent proper oxygen flow

Most transfer cups and bags are not well-ventilated. As a result, these temporary items usually prevent proper oxygen from circulating, which can have dire consequences for your betta if you wait too long.

The moral of the story is to get your betta home to their new tank quickly. The faster you can transition them from cup to tank—the better.

How to Safely Transfer Your Betta Fish

When you’re moving your betta fish from the transfer cup into the tank, you need to take a few precautions. Drastic water temperature differences can shock your betta’s system, causing adverse outcomes.

Transfering must be done quickly, efficiently, and correctly. This task is time-sensitive, but you also can’t cut corners.

How to Acclimate Your Betta to New Water

You never want to drop a fish into unfamiliar water and walk away. You need to make sure you’re taking the proper steps to get them acclimated safely.

Bettas need to live in water between 75 and 85 degrees F, as these are tropical fish. Therefore, keep pH levels between 6.8 and 7.5, testing periodically.

Once you make sure the water temperature and pH levels are adequate, it’s time to transition your betta to their new habitat slowly. It’s vital to reduce lighting to minimize stress during the transfer period.

Switching Water Slowly

If you have a betta in a bag or cup, the idea of water switching is to slowly allow the tank water to merge with the cup water.

  • Create a barrier between your fish and the tank water.
  • Slowly add a half cup of tank water to the transfer cup every 15 minutes.
  • Use this method for no less than 30 minutes.
  • When you’re ready and the conditions are right, gently lower the betta into the tank.

Note: Never pour the betta into the tank from above the water. That can cause a great deal of stress. Instead, take the cup or bag and slowly submerge the fish into the aquarium.

paradise betta
Image Credit: lmstevendesign, Pixabay

Do Betta Fish Require a Filter?

Betta fish are one of the few in a domestic setting that can live without a filter. However, if you decide not to use a filter, you need to keep the tank clean and debris-free by changing it frequently. Dirty water can carry bacteria that can be very detrimental to your betta.

Only you can decide if a filter is a good idea for your setup. It can make your life a lot easier, making periods longer between complete tank changes. It can also reduce algae buildup on the surfaces too.

If you choose not to have a filter, aquatic plants can be terrific alternatives.

divider fish plants 2

How Long Should You Wait to Put a Betta with Tankmates?

Bettas don’t usually play well with others, though there are exceptions. It would be best if you never put the betta directly into the tank right from the pet shop. Always make sure you have a separate tank for your betta to stay in and come back to if introducing them to new tank mates is unsuccessful.

Mixing unfamiliar fish without a proper introduction is a recipe for aggression and contamination. Therefore, you should wait a minimum of 2 weeks before placing bettas in a tank with others. Also, it’s important to do your homework about betta compatibility.

Quarantine Period

To reduce the transmission of disease or stun the fish, slow introductions are essential. That means all new fish should undergo a quarantine period where you observe them. A reasonable time frame is 2–4 weeks, depending on behavior.

Red betta fish and moss ball in a bowl
Image Credit: mkzdillon, Shutterstock

Compatible Tank Mates for Betta Fish

Betta fish can sometimes be frisky, so they don’t make the best tank mates in some scenarios. For instance, fish with long, flowing fins (such as goldfish) can trigger aggression in these fish, mistaking it for a challenge.

Here is a small list of compatible mates:

Other Creatures
  • Frogs
  • Snails
  • Shrimp
  • Slugs

betta fish_ivabalk_Pixabay
Image Credit: ivabalk, Pixabay

What to Do During & After Transfer

When you’re ready to introduce your betta to a group of new friends, it has to happen slowly. However, there are some measures you can take to ensure everyone stays safe and sound in the process.

1. Offer a Feeding Distraction

As you let the betta into the tank, distract other critters by feeding them. That way, the new betta can slip away into hiding to begin the adjustment.

2. Continually Monitor

You need to make sure you try this when you will be home and close by for a few days. First, you will have to make sure the new betta is adjusting well to their new environment. Then, if you notice any odd behavior that could be linked to stress, you must act by separating the fish.

betta fish inside aquarium
Image Credit: Yan Cabrera, Pixabay

3. Watch for Signs of Territorial Aggression

Bettas can have territorial aggression, and they are known to be temperamental fish. So if your betta, or any other fish, is causing trouble, you have to prepare to house your betta in their own tank.

wave tropical divider


Bettas are absolutely stunning fish with visually pleasing colors, patterns, and fin structures. They would make any setup a beautiful one, but they might not always be compatible with other tank life.

Whether from cup to tank or a single tank to a community tank, any transition should be handled with utmost caution and care. But as long as the conditions are right and you’ve followed all the steps, your betta should acclimate in no time.

Related Read: How to Transport Betta Fish (Tips & Tricks)

Featured Image Credit: Remy Roma, Shutterstock

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