How to acclimate freshwater fish

Learn how to acclimate your fish correctly and minimize your stress in a new environment.

Tips for purchasing a new fish, too.

It isn't easy to go from one setting to another. It's terrible to be in a bit of a bag and get in a vehicle during the changeover.

So, what can you do to reduce stress during transition and acclimation?

Actually, Local Fish Store (LFS) Fish Acclimation begins right at your LFS. Take the time to inquire about their water parameters to know how close they are to your water conditions at home or how different. If there are minor variations, the acclimatization may take 30 minutes. However, you will want to take your time and gently acclimate your new fish if the differences are significant.

Make sure you ask the shop what their salinity is, especially with saltwater fish, and if they utilize copper.

Salinity Check

Different fish shops maintain fish in various waters. The characteristics of seawater, pH, and salinity are very severe. Some shops retain fish at lower salinity for easier breathing and utilize copper to produce sterile surroundings. While this seems lovely on paper, it is really quite stressful for your fish when acclimatized to your tank. Most fish do not go from low to high salinity since it takes more breathing effort and energy.

Moving from a sterile, copper-treated environment to an unmedicated tank means the fish are suddenly exposed to illnesses and parasites. The fish was in a sterile and "breathing" environment at the fish shop; now, it is impossible to breathe in a disease-filled environment. There is often additional stress created by the fact that current tank mates also select new fish. Combining these variables is why so many fish from the fish shop has suddenly become ill after being put into a tank.

We maintain our saltwater fish at a salinity comparable to yours at Glass Aquatics: 1.023-1.025. We don't treat copper or other drugs in our showcase tanks. Although we cannot prevent the pickup of your new fish by your current fish, we can ensure that we do not give you "artificially healthy" fish that are difficult to acclimatize to and may quickly get ill. We also have a vitamin B booster injection in-store to minimize stress on fish while traveling.

Floating fish

Now that your new fish is home, it's time to acclimatize them and put them in the tank. We advise you to float the bag for 15 minutes, unzip it and place water and fish in a container for acclimatization. The water will probably contain ammonia, so putting a few drops of water in the acclimation container (most water conditioners, such as the Glass Aquatics Water Conditioner or the Sera Aquaman, will also neutralize ammonia).

Acclimation in the cup

Add a cup of water from your aquarium to the acclimation container for freshwater fish. Allow the fish to acclimatize and add another cup of water from your tank for ten minutes. Netting fish and putting the fish into your tank another ten minutes later.

We strongly suggest drip acclimatization for saltwater fish. The Innovative Marine Accu-Drip is designed for this purpose alone. Test the water salinity in the acclimation container, then test your aquarium for the salinity of the water. We suggest that salinity variations not exceed 0.02 per hour to increase salinity. If your salinity is 1.018, you should be able to prepare your fish for a 3-hour drip acclimation, and your salinity is 1.024.

For minor variations in salinity about 0,001-0,002, start dripping and let the water volume treble the initial capacity in the container. Discard half the water and drip it for another half an hour. You are prepared to net the fish and place it in your aquarium afterward.

Use a slower drop rate and repeat the procedure more than 2-3 times before netting and putting it in your aquarium for more considerable salinity variations.

Fish Netting

If the fish was in a hypersalinity shop (1.009-1.011), putting up a quarantine/acclimation tank would be very uncommon. The acclimatization tank must have the same pH and salinity as the water in the bag. Float the bag for 15 minutes before dripping in the acclimation tank for 30 minutes an hour before introducing the fish. During a week, gently increase your water salinity by cleaning the saltwater acclimate tank and/or removing some low salinity water and replacing it with higher salinity water every day until the salinity of your aquarium matches.

Tank quarantine

Turn your aquarium lights down just before the fish is put into the aquarium, and don't turn them on or feed the tank until the following day.

Lights Off  Then...

Following these procedures, the likelihood for your newly acquired fish to become a happy and healthy permanent resident is considerably greater.

Learn how to acclimate your fish correctly and minimize your stress in a new environment. Tips for purchasing a new fish, too.

It isn't easy to go from one setting to another. It's terrible to be in a bit of a bag and get in a vehicle during the changeover.

How long would it take for an aquarium to acclimate fish?

It's usually thrilling to purchase fish for your aquarium, however many reports that their fish die shortly after entering the tank. You can't just throw a new fish into the aquarium and expect it to thrive.

You must first learn how to acclimate a fish to the aquarium to guarantee that your new fish survives in its new surrounding. A seamless transition is an ideal method to bring fish into their new home.

Many individuals will tell you that fish can acclimatize to an aquarium in approximately 15 minutes. Although this is partly accurate, it takes a new fish at least an hour to fully adapt to a new habitat.

Float the bag in the aquarium until the water is equal to that in the tank. Give the fish ample time to adapt every 5 minutes by adding a little aquarium water to the bag.

For larger fish, it may take much longer.

Fish Acclimatization

A few essential measures are needed to guarantee that your fish acclimatizes without any difficulties to your aquarium. The entire procedure needs you to be patient and careful.

Rushing the procedure may give your new fish shock and worry

Dumping fish straight into the tank with pet shop water is not a smart idea. It may include illnesses and parasites which are not transferred to your aquarium.

You may adequately acclimate your new fish to your aquarium by following these easy steps:

  • Preparation before the fish are introduced to the aquarium.
  • If you purchase new fish from your pet shop for the first time, you should bring it home immediately. This is due to the lack of adequate oxygen in the plastic bag and the lack of fish.
  • After you have brought it home, lower the lighting in the room and turn the aquarium lights off.
  • This prevents shocks or damage to fish due to abrupt illumination changes.
  • Once your fish gets used to the new surroundings, the illumination may be less cautious. However, it is preferable to first expose your fish to a dark environment.
  • Next, rinse the outside of your fish's plastic bag. This prevents contamination of aquarium water by putting the bag inside. Put the extra water out of the bag but leave enough to cover the fish's dorsal fin.

Float the bag in the tank

  • The next step is to unzip the bag and roll the top down four or five times to float without sinking in the aquarium.
  • Place the bag in the tank and let it float for 15 minutes. If you believe the bag is still unsteady in your aquarium, it may float on top of the water with a few additional rolls.
  • The water in the bag will eventually reach the same temperature as the water in the aquarium if the bag floats in the aquarium water. The open-top allows oxygen to reach your fish.

Add water to the bag

  • After 15 minutes of letting the bag float in the aquarium, you need to add half a cup of aquarium water to the bag.
  • Wait and do it again for 5-10 minutes. This lengthy procedure allows your new fish to adapt progressively to changes in the composition of temperature and water etc.
  • If it is taken as slow and steady as necessary, its chances of survival will improve. It will adapt to its new environment without stress or shock. Continue to add aquarium water to the bag every five to ten minutes until the bag is full.
  • Remove the bag, dump half the water in the sink and float it in the tank again. Continue to add half a cup of water to the bag every 5-10 minutes. Repeat until you are confident that the water in your bag has the same temperature as the aquarium water.
  • Your fish is now ready to travel to their new home.

Put the fish into the aquarium

  • You will need a small net to release the fish into the tank.
  • Dip the net into the bag, take the fish carefully out of the bag, and put them in your aquarium. Use a leisurely swooping technique to lift the fish carefully. Make sure the fish won't get stuck in the net.
  • Even if you are delicate, remember to be fast while transferring the fish to the tank.
  • You can't keep your fish long out of the water. The bag may be held over the water surface of the aquarium and transferred rapidly from the bag to the tank using the net.

Why do you need your fish to acclimatize your aquarium?

Your new fish need to adapt, not just the aquarium water temperature. More makes it essential to acclimatize your fish to a new environment for their survival.

Here are some additional reasons that need this process:

1- Water Composition Aquarium

All fish species need to establish water conditions in an aquarium to thrive. You must ensure that water conditions are ideal for the fish before adding additional species into your aquarium.

More fish perish from a pH shock than any other cause if people put them in an aquarium for the first time. Gradually adding water to the bag controls the temperature and adapts the fish to the pH value of the water, hardness, and presence of other chemicals.

The easiest way to test the water is to put a new fish in the aquarium. This will help you guarantee that the water conditions and the composition for the kind of fish you bring into the aquarium are suitable.

2- Community pre-existing in the aquarium

Another reason why acclimation is required is to ensure it works with the current aquarium population.

Fish are not usually calm to other fish and friendly. If you already have fish in your aquarium, they may not be glad when a new fish is added to the tank. You may see your new fish as an invader.

Putting in the aquarium a bag holding the new fish will offer you the opportunity to get along and become acquainted.

If the current community fails to accept a new member, there is at least a barrier between them and the new fish.

3- New Sounds

Fish are sensitive to noises, like lighting.

The sound of the filters and waterfalls may bother your new fish a bit since they are new in this environment.

The plastic bag will mask these new noises to a large degree, making the fish acquainted with the new sounds. This prevents the fish from being shocked or stressed.

What happens if you don't acclimate fish and How long do you leave fish in the bag before putting it in the tank?

Whether you've recently purchased new freshwater fish, saltwater fish, invertebrates, or coral, acclimatization plays an essential part in your new addition's long-term health and survival.

I like to get a new animal for my reef tank, however, it is a lengthy trip from shop to home for me. When I purchase them in town, this is at least a 3-hour trip home. It's a 24-hour transportation procedure when I buy them online. Acclimatization is not an option for me.

Common Fish Symptoms Not New Aquarium Acclimated:

Environmental Acute Factors

Most fish farms have significantly different water conditions than your tank. You do this to minimize stress and the likelihood of infection since an animal loss affects its end.

Fish may endure these lower characteristics for short durations, but the difference between your water and its parameters might be considered as a result. If the two sets of water characteristics are significantly dissimilar, a slow acclimatization time is needed.


As essential as the acclimatization of new fish in the aquarium, this procedure is also required. Never put the fish into the tank immediately.

This may cause your new fish discomfort and distress. Worse, if you do not acclimate them appropriately to their new habitat, you may kill your fish.

Patience, care, and steps are essential to make your fish in a new environment more comfortable.