Best Way To Acclimate Your Betta Fish

What does it mean to acclimate your betta fish?

Acclimate means to get the betta used to the new temperature and water chemistry in your new aquarium. Any sudden change can kill your fish. Please read on to learn how it is properly done.

How to acclimate betta fish

You finally got your new betta fish from a pet store or through the mail. You want to transfer him or her into your community freshwater aquarium or a new aquarium just for your betta.

Whatever you do, do not open the bag or cup and just dump the betta in. Although some bettas are tough enough to survive this process, most will promptly die, from shock from the sudden temperature change and change of aquarium water parameters. 

It takes time to acclimate your betta to his or her new home. Try to be patient and enjoy the process. The best way to acclimate your fish is by floating the bag or cup on the top of your tank’s water.

Floating Method of Acclimation

This method should be done when adding a betta to a tank where he or she is the only fish, a quarantine tank (more on that below), or into a community aquarium.

  • Turn off the lights in the tank and, if possible, in the room the tank is in. This helps keep down your new betta’s stress levels. Your betta will be stressed just because of the move.
  • Float the bag or plastic cup in the tank water for about 15 to 20 minutes.
  • Open the bag or cup and place some water from the tank into the bag or cup. Try to get a half-and-half mixture of new to old water in the bag or cup. 
  • Float for another 15 to 20 minutes.
  • During this time, get a bucket or clean container used for just transporting fish. It should only ever be cleaned with water, never soaps or detergent. 
  • Get a net.
  • Take the bag or cup with your betta and pour it into the bucket. The water is filthy and should not be placed into your aquarium.
  • Net the betta and place gently into the aquarium.
  • If you have other fish, feed them now. This way, they are preoccupied with the food and not interested in bullying your new betta. Your new betta most likely will not eat but hide.
  • Do a 10 to 25% partial water change. This will also help your new betta get acclimated to the new water chemistry he or she is now living in.

And the Not So Clever Acclimation Method I Used Years Ago 

The method I used years ago was to float the bag, add a few handfuls of water every now and then, and then just overturn the bag, water and all, into the aquarium. I usually waited a day or two to do the partial water change. Looking back, it’s a wonder any fish survived.

And then there was the time I bought five feeder goldfish for the goldfish tank my Dad gave me when he moved. I was floating the bag and had undone the top because it had been an hour since they went into the bag and I was paranoid that they wouldn’t get enough air. 

One of the goldfish, who I named Napoleon (smallest and bossiest), started tapping at the bag. Slowly, the bag tipped over. Napoleon kept on tapping. Finally, the bag tipped over enough that the fish promptly swam out of the bag and into their new home.
I know I should have upended the bag and fastened it shut, but I was entranced watching Napoleon figure out how to get out of the bag. 

Although one fish died within a month, most of the goldfish lived for years. Napoleon was about 10 when he died. The last of the five lived with me for 13 wonderful years. 

Oh, by the way – never keep a betta with goldfish. They have vastly different needs.

The Quarantine Tank

If there aren’t any other fish in your tank, then you can just skip this part for now, unless you plan on soon getting a larger community tank. For bettas, this can be a small aquarium of even one gallon, as you do partial water changes every day. For larger tanks, you can take longer to do partial water changes.

It’s best to quarantine any new fish in a small tank for two or three weeks. This will give you enough time to see if the new fish is sick or carrying parasites. You don’t want a new fish to kill all of your beloved old fish.

Your quarantine tank does not need to be fancy. You do need for it to have these things:

  • Filter, unless you plan on changing the water every day.
  • Heater, because bettas do best at 80 degrees F.
  • A place for your betta to hide, such as an artificial plant or tunnel ornament. Your betta will be stressed from the move and will be able to relax in a hideout.
  • A net for when you move your betta.

Acclimation From the Quarantine Tank

Be sure to use the water from the same source and use the same water conditioners in your quarantine tank as you do for the community tank you want to place your new betta in. This way, acclimation is complete.

Just net your betta and gently place it in the community tank. If your community tank is more than a few steps away from the quarantine tank, then transport your betta in a bucket or container that is only used for this purpose. 

Be sure to use water from your quarantine tank or community tank for the transportation bucket. 

Just Say No to Drip Method Acclimation

Once upon a recent time, drip acclimation was the hip way to acclimate fish into a new aquarium. You spent an hour or so slowly dripping water from your aquarium into the bag where your new betta waiting. This method has killed many fish.

Why? Because the drip method acclimation process causes a major spike in ammonia inside the bag where your new betta is waiting. Your betta has been shedding waste in the form of poop and exhalations in a very small amount of water. He or she needs to get out of that bag as soon as it’s safe. It’s safe to get the fish out long before the drip acclimation process finishes.

If you remember nothing else from this article, please remember this – never drip acclimate your new fish.

Frequently Asked Questions About How to Acclimate Betta Fish

How Should I Transport My New Betta from a Pet Store?

It’s best to bring a small soft-sided cooler to transport a betta. This helps keep the betta in a dark and partly temperature-controlled environment. If you forgot to bring a cooler, and the pet store is less than a half-hour drive from home, keep the betta in the store’s bag. Keep the betta in the bag all the way home so it’s dark. Go right home from the pet store. 

What Happens if I Don’t Acclimate My New Siamese Fighting Fish?

Most likely, your betta will die. The water in the bag or cup has different temperature chemistry than the water in your tank. Any sudden change will put your betta into shock and kill him or her.

How Long Can Bettas Survive in a Transportation Cup or Bag?

Bettas, and fish in general, can survive for a surprisingly long time in a bag or cup. Bettas from a fish store can live up to nine hours, depending on how much they poop. Bettas shipped through the mail are usually not fed for a couple of days before shipping so that they do not poop and cause a huge ammonia spike. Bettas have been known to live for three or four days in their bags if shipped properly.

How Long is the Floating Acclimation Process?

It usually takes about 45 minutes to an hour.

How Long Should I Quarantine My New Siamese Fighting Fish?

About two to three weeks. 

Why is My New Betta Fish Not Eating Even After I Acclimated Him?

Moving to a new home is incredibly stressful for a fish, even a tough fish like a betta. It may take a few days before he or she starts to eat. Keeping the lights off helps to calm them down.

How Do I Know if My Betta is Stressed?

Your betta will be pale, prefer to hide, often spends time on the bottom of the tank, and won’t eat. Stressed bettas often show stress barring or dark lines that run horizontally from head to tail. 

How Should I Acclimate Bettas That Come Through the Mail?

Use the same methods you would as if you bought the fish from a pet store. Use the floating bag method. Many fish breeders or online sellers will also include acclimation instructions. Good fish breeders and sellers will gladly answer questions about acclimation before you buy any fish.

If you want to learn more about betta tanks, please visit our collection of articles here.

About the author

Hi, I am Rena.
I grew up in a house surrounded by fish tanks.
I have spent my life caring for and writing about fish.
I have studied journalism and worked for online and print magazines.

You can find the articles I wrote here