How To Acclimate a Fish the Stress-Free Way

There are many techniques for acclimating a fish to a new tank, but the ultimate goal is to have them adapt in a way that’s the least stressful for their system. However, the acclimation process starts long before you bring your new fish home. Learn how to acclimate a fish the stress-free way so that you can ensure they stay healthy in their new tank.

Talk to the Seller

The first step you’ll want to take is to inquire about the fish’s environment at the store. Ask about the water temperature, salinity, and pH. Additionally, asking whether or not the seller used copper in the tank to create a sterile environment is critical. A sterile environment is easier on the fish, but acclimating them to a tank with natural bacteria will shock the system of a new fish. The larger the differences between your tank and the seller’s, the longer the acclimation process will take.

The First Few Steps

Whether your fish is freshwater or saltwater, you’ll want to float their bag in the water for 25 minutes so that the water in the bag is the same temperature as the water in your aquarium. Then, place the fish along with the bag water in a sterile container. To cover all your bases, add a few drops of water conditioner into the container to neutralize any harmful toxins.

Saltwater and freshwater tanks and their fish are very different, so the next few steps will also look different.

How To Acclimate Freshwater Fish

Your next step is to add a cup of the tank water to the container every four minutes. Once the container is full, gently remove half of the water and repeat the process. Once you’ve completely replaced the water in the container with aquarium water, you’re ready to add the new fish to your tank. You can choose to either net the fish or slowly submerge it in the container.

How To Acclimate Saltwater Fish

First, test the salinity of your tank, and then test the salinity of the water in the container. If the container salinity is lower than the aquarium salinity, increase the salinity level of the container by 0.02 per hour. You’ll need a drip acclimator to control the speed at which the salinity increases. Once the levels are the same, discard half of the water in the container and repeat the process. For tanks with a substantial salinity difference, you’ll have to repeat this process two or three times until the salinity levels are the same.

With this guide to acclimating your fish the stress-free way, you’re ready to add new fish into your aquarium. Just be sure to keep an eye out for any tank mate bullies, and your fish should be healthy and happy for years to come.

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Written by Logan Voss

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