Restocking the Aquarium is Simply In the Bag

Acclimating new fish in a tank during restockingOK, so you just bought some new tropical fish for restocking your freshwater aquarium, and you want to get them home and into the tank as soon as possible.

So you race right home, open the bag and dump them right into the tank right?


There is a right way and a wrong way to introduce your new tropical fish to your fish tank, and what we just described is very much the wrong way. Some gentle preparation is in order to move those new fish into their new environment safely.

When Restocking, Acclimation is the Key

The purpose of acclimation is simple: the water that the fish or corals are packaged in has different temperature, pH, and salinity parameters than your aquarium. Fish, and especially invertebrates (including corals), are very sensitive to even minor changes in these parameters, so proper acclimation is the key to ensuring their successful relocation.

Of course, this whole process begins with selecting some healthy fish from your local aquarium specialist. Take special care to make sure the breeds of fish that you have are compatible and get along. Most pet stores are staffed by knowledgeable clerks and attendants who can help you pick out fish that will be able to share a tank without causing one another harm.

Now that you have chosen your new fish, the process begins, bringing them back to your home is an important part of the process of preparing them for their new environment. As you transport your new fish home, make sure you cover the bag with something to help reduce the stress experienced by the fish during transportation.

Once home, let the bag float in your tank for 15 minutes to a half hour, allowing the fish to get used to the temperature of the water in your tank. Certainly the water in the transport bag will be remarkable different in temperature from the water in your tank, so this process of acclimation is very important.

Equalize the temperature

After the temperature equalization, open the bag and being very careful not to spill any of the water into the tank, get a clean cup and put some tank water into the bag. You will want to put an amount in the bag about equal to what already was in it, thus approximately doubling the volume. Allow the bag to float for another 15 minutes.

Now take the bag out of the tank and open it to allow you to reach in with a net. Gently scoop up your new fish with your net and withdraw the net from the bag, allowing the net to simply rest in the water until your new fish swim out of it and into their new habitat.

Repeat this process until you have brought all of your new fish from the bag into the tank.

Once you have completed the transfer, it is very important that you do not empty the remaining water from the bag into your tank. This water may contain germs or diseases from the pet store, which may result in a deaths or illness to your fish.

So there you have it! A simple restocking method for introducing your new fish into their new habitat safely! Follow these simple step for an easy and enjoyable time with your tropical fish tank!