What Happens If You Don’t Acclimate Fish?

Acclimation is essential in introducing a new fish into the tank. Aquarists at one point or the other try to add fresh fish to their tank. Acclimation is one of the crucial steps that precede the introduction of new fish into your container.

What Happens If You Don’t Acclimate Fish?  Adding fish into a new tank without acclimation can make the fish go into shock, it can cause stress to the fish, it will also cause deterioration in the health of the fish. Worse case it can lead to the death of fish within a few days in the tank.

Aside from the effect on the fish, introducing fish to a new tank without acclimation can directly or indirectly add pests and parasites to the tank. Likewise, you can use the period of quarantine to observe the specific behavior of the new fish before exposing your existing tank members.

What Happens If You Don’t Acclimate Fish

The best of this scenario is that few aquarists get away with this action. Most times, aquarists don’t get away with introducing fish to a new tank without acclimation. The best sequence you can follow to ensure the safety of existing tank members and the fresh fish is to move the fish from the nylon to the quarantine tank, then to the main tank.

What Is Acclimation?

Acclimation is the process of accustoming and allowing your fish or other living things to get used to new climates or new conditions. Acclimating fish before introducing it to new tank conditions will help the fish adjust and learn how to adapt to the new specifications you want to add them to for a long time.

All living creatures need time to adjust and slowly adapt to their new environment. That is why adaptation is one of the critical characteristics of living things. If fresh fish find it hard to cope in the new tank when exposed to a drastic change, they can die off within a few days in the new tank.

Acclimating your new fish means you are reducing stress and shock of the new environment, and you are giving them a better chance of survival. Likewise, not only fish need acclimation. Other tank members such as snails and even some plants need this treatment before introducing them into the tank.

How To Acclimate New Fish In The Aquarium

It is a common occurrence for new fish to die a few moments after they get into a new tank, and you expose them to new conditions. This change is often too drastic for them, and they might find it pretty hard to cope. Consequently, aquarists are advised to acclimate their fish before exposing them to a new condition.

Acclimating is not a complicated process; neither is it challenging nor demanding. You should quarantine and acclimate new fish for at least two weeks. If you have an extra tank, it is also essential to observe the general behavior of the fish, especially if you intend to introduce them in a community tank.

You can acclimate new fish in three necessary steps;

STEP 1: Open The Bag: As simple as it sounds, it is the first step to anything you want to do. New fish often come in bags that are usually in a container sealed with rubber bands. After you roll open the top of the bag, expose it to fresh air for a couple of seconds. This folding will allow the bag to float on its own and give a few more folds if need be.

STEP 2: Add Water from Your Existing Tank to the Bag of the New Fish: this is the most critical of the acclimating process. It has to be slow and steady for you to get effective results. Start by scooping about ½ of water from the tank and slowly pour it to the bag. Pause for about 15-20 minutes before repeating the process.

The slow but steady process will allow the new fish to learn about the factors of the freshwater like pH, temperature, oxygen and nutrients level, salinity, and in some cases, the lightning. This process is best if you have an extra tank to use instead of the nylon bag. Also, ensure that you take your time and not rush this process because it boosts the survival chances of the fish.

STEP 3: Check The Water Condition Of The Tank: Each aquarium fish have the water and tank conditions that are suitable for their health and growth. You should understand the fact that acclimation will not change the optimum condition for the survival of your fish. Instead, it will only allow them to get used to a new environment.

For instance, you cannot acclimate a freshwater fish to a saline environment. Consequently, you should test the water quality, temperature, pH, nitrate level, water level, space, tank space, nutrient level, and so on to ensure that they are suitable for the new fish.

Benefit Of Acclimating New Fish

There are several benefits that both aquarists and new fish derive from acclimating, and they include;

  • Acclimating boosts the survival chances of the fish in a new tank.
  • It reduces the possibility of shock, stress, and a general deterioration in the health of the new fish that can invariably lead to their death.
  • It helps aquarists observe the behavior of the fish before introducing them to a community tank.
  • Likewise, it can help you determine suitable tank mates for the fish judging from their behavior.
  • Quarantining the new fish in a separate tank for about two weeks will reduce the possibility of introducing sick fish, pets, or parasites into your container.


Just like every other living thing, adaptability is one of the key characteristics of any aquarium fish. If you are introducing them to a new environment, you should ensure that you help them adjust to the new environment rather than drastically changing their environment.

Acclimating aquarium fish will boost the survival chances of the new fish; reduce shock or death due to drastic changes in the environment.