Acclimate Fish To A New Aquarium – Using the “Float the bag” method for goldfish

Whether you are stocking up for a new set up and cycled aquarium, or adding into your current goldfish family, there are a few things that you should consider when bringing back a goldfish.

The first thing is about quarantining it, more so when you already have an established goldfish family. The purpose of doing this is to protect them from a possible disease outbreak. Seriously one little shortcut of not doing that may lead to disaster. Learn from my mistake.

The second thing is about acclimating the newcomer. Do you know what acclimate means and why you need to do it? Please read on as I will be explaining about it and about the “float the bag” method to acclimate fish to a new aquarium.

Acclimate fish to a new aquarium

Acclimate Fish To A New Aquarium

What does acclimate means?

Acclimate means to adjust or to adapt to a new environment or situation. In the case of your goldfish, the first thing that it needs to adjust to when being put into a new aquarium is the temperature of the water. This applies to any aquarium no matter whether it’s main or quarantine.

Why do we need to acclimate fish to a new aquarium?

Whether we get our goldfish from fish stores, through online or from another person, we must remember that it has already gotten used to an old environment before. Then it was packed and made its way to us, and got put into a new environment (hopefully one which is already cycled!).



Putting it into the new environment immediately can cause your goldfish to encounter a sudden change of temperature, and this gives it a shock and stresses it out. Remember that it already had its share of stress from getting caught, packed and transported, so this is like adding more of it to that poor fish. Like us, stress is never a good thing.

So the better way is to acclimate your new goldfish first, as this gives it some time to get used to the new temperature before going in.

Using “Float the Bag” method to acclimate goldfish

“Float the bag” is a well-known general method used to acclimate fish to a new aquarium, and it is also the simplest. When you get your new goldfish, it will usually come in a well tied up or sealed plastic bag. Please keep the bag tied up or sealed when acclimating.



So to acclimate it with the “float the bag” method:

Step 1: If the aquarium is brightly lit, either turn the lighting off or adjust it so that it is dimmer. Your new goldfish is already stressed, so putting them under bright light will certainly NOT help.

Step 2: Take the bag that your goldfish comes in (i.e. still tied up or sealed) and place it into the aquarium’s water.

Float the bag

Step 3: Let the bag float in the aquarium (hence the term “float the bag”) for at least 15 minutes. This is to allow the water in the bag to slowly adjust to the water temperature in the aquarium. As the temperature change is gradual, your goldfish will not get shocked.

Step 4: After 15 minutes, untie the bag and quickly but carefully take the goldfish out and put it into the aquarium. Be careful not to pour the water from the bag into the aquarium, as you do not want to introduce any possible pathogen to it.

Calico Butterfly Telescope

See how simple this method is to acclimate fish to a new aquarium?

Although this “float the bag” method is commonly used, it is not applicable to all aquatic pets. For more sensitive aquatic pets such as invertebrates, they are better off with another acclimating method such as the Drip method which is of more hassle.

However for goldfish, the “float the bag” method works well enough!

So, how do you acclimate fish to a new aquarium? Do you have any other methods besides “float the bag”? Please share your experience and comment in the section below.

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