How to put a betta fish in a new tank

betta in a transportation bag

Don’t drop it straight in!

When adding a new betta to an aquarium, it’s always best to acclimate it first. Simply adding the fish straight from the transportation bag to the aquarium without acclimating it can be a big risk. The sudden change of water and temperature can stress the betta and shock its body.

Fish can stress a little anyway when being added to a new aquarium as they are in a new environment, a new home and, for a betta, a new territory. You therefore want to reduce any other stress as much as possible, and the smoother the transition, the easier it will be on the betta.

Let’s have a look at how to put a betta fish in a new tank with minimal stress, and how to make it feel at home more easily.

What is acclimation?

Acclimation is the process of slowly adding the betta to the aquarium from the transportation bag or container. This allows it to gradually adjust to the water temperature and conditions.

How to acclimate

It’s easy!

  1. Untie the knot/rubber band that has been used to seal your transportation bag. With the betta still inside it, sit the transportation bag in the aquarium water. Make sure the top of the bag breaches the surface so that water doesn’t flow into it from the aquarium. You may need to hold the bag yourself during the acclimation process, or you can sometimes hook the top of the bag over the side of the aquarium to keep it stable.
  2. Add about 150ml of your aquarium water to the bag/every 5 to 10 minutes. Do this for about 25 to 30 minutes and then release the fish into the aquarium.

Note: If your fish has been transported in a plastic container, you can still follow the instructions from step 2 above, but with the container stood next to the aquarium instead. You simply add the water to the holding container, instead of the bag.

If it’s the case that the transportation container isn’t big enough to follow the steps above, either reduce the amount of water added every 5 to 10 minutes (to 100 ml, for example) or if it’s a really small container, transfer the fish to a larger container for the acclimation process. Make sure the container is clean, has not been previously used as a container for cleaning products, and is thoroughly rinsed with a bit of aquarium water or fresh water before adding the fish.

A quick note on fish transportation bags:

Transport bags tend to be a clear plastic bag, with a length three times the width of the bag.
In any professional aquatics store, about 30 percent of the bag will be filled with water, the betta will be placed in the bag, and the remainder of the bag will be used to tie a knot, securely creating an airtight environment for the fish.

In the UK (where Bettaboxx is based) bettas will nearly always be sold, both in-store and online, in these standard aquarium bags. We understand that this isn’t always the case in other countries. In fact, in some cases bettas can be delivered and transported inhumanely. This has been recognised by many passionate hobbyists and we will help to fight against the ways these animals are sometimes kept and transported in poor conditions.