Add New Tropical Fish to Your Tank

Expanding your home aquarium and adding new tropical fish is a fun project, but it should be handled with care. The fish should not be released into the tank immediately. The process requires that you complete a few methodical steps to ensure that the new fish is happily and safely situated in its new home. Preparing your tropical aquarium, selecting the right fish, and providing an easy transition will help ensure the health and safety of your new fish the fish already living in the tank.

Steps

Planning Ahead

1. Ask an expert. If you wish to add new tropical fish to your fish tank, you should discuss the process with an expert at your local pet store or ask your veterinarian. Many fish are territorial and may exhibit possessive behavior if they are housed in a crowded tank. A veterinarian or expert will be able to help you decide what type of fish will be compatible with your fish tank and what type of fish will happily co-exist with the creatures already living in the tank.
   • Angelfish, for example, can be aggressive fish. They may exhibit territorial behavior toward particular types of fish, and they may even be aggressive toward their smaller tankmates.
   • Serpae tetras, another type of tropical fish, can also be a bit of a bully. They often nip at the long, flowy fins of other fish, such as Angelfish and betta fish. Serpae tetras typically get along with other, similar-sized tetras and bottom-feeder fish.
2. Research how large the fish will grow. It is important to research the type of fish you would like to add to the tank, particularly how large the fish will grow. Be sure that your tank will provide enough room for the fish’s growth and that it will adequately house it once it reaches its full size.
3. Check the water quality. Use a testing kit to check the quality of the water. These kits can be found at your local pet store and include testing strips and a key to help interpret the water levels. The chlorine level in the tank should be at zero before you add new fish, and the pH balance should be equal to the pH balance of the water where you purchased your new fish.
4. Monitor the water temperature. Tropical fish thrive in waters that are between 76° to 80°F, or 25° to 27°C, so using a tank heater and having a thermometer are crucial. Some species require that the temperature be adjusted slightly, so be sure to find out the proper temperature for your new fish.
   • A submersible or a hang-on heater can help regulate the water temperature, which is particularly important during colder seasons. Be careful not to overheat the water in the warmer months.
   • Use a stick-on tank thermometer to check the temperature regularly.
5. Transport your new fish safely. When transporting the fish home, it is important to take a light cloth or towel with you so that the bag can be covered. This helps minimize the stress a fish can experience when being transported to a new location. Also, be sure to keep the journey home as short as possible. Getting the fish safely transported in a reasonable amount of time will help lessen the stress and trauma.

Using a Quarantine Tank

1. Quarantine the new fish. Before adding your tropical fish in the main tank, you may wish to house the new fish in a separate tank for a couple of weeks to ensure that the fish is healthy and will not transfer any diseases, bacteria, parasites, or infectious diseases to the other creatures in your tank. This also offers a chance for a new tropical fish to recover from the stress of being transported before joining the other fish in your main tank.
2. Create similar tank conditions. Be sure that the pH levels and temperature are similar to the levels in the main fish tank and use a similar filter and heater. This will allow your fish more time to adjust to the new atmosphere.
3. Do not use rocks, sand, or gravel. Do not place anything on the floor of the quarantine tank if you are treating your new fish with any medications. Sand, rocks, and gravel can absorb copper salts and then release them later on, which can interfere with the medication.

Introducing the New Fish

1. Lower the tank lights. Adding a new fish to the tank can be stressful for both the new fish and those who have already made their home in the tank. To help make the introduction as stress-free as possible, lower the tank’s light or turn them off completely before introducing new fish. This will help create a less hostile, less stressful environment.
2. Introduce new fish one at a time. Never buy several new tropical fish at once and add them to your tank. If you overload your tank, this can upset the pH balance, the ammonia levels, and the quality of life for the fish and other creatures.
3. Place the fish bag in the water. Let the unopened fish bag float in the tank water for about 30 minutes. This will help your new fish adjust to the temperature of the water in the tank. The water they have been housed in will be a different temperature from the water in your tank, so this process of acclimation is important.
4. Pour some tank water into the bag. After the fish has acclimatized to the water temperature, keep the bag afloat in the tank. Slowly open the bag and pour about ¼ of a cup of tank water inside, taking care not to spill water into the tank. Every 15 minutes or so, add another quarter cup of the tank water into the bag. After an hour, your new fish should have adjusted to your tank’s water chemistry.
   • The water from the quarantine tank should be kept separate from the main tank’s water supply in case there are any parasites or bacteria in the quarantine tank.
5. Give your fish a freshwater dip. The water from the quarantine tank may contain parasites or bacteria that may harm the other fish in your tank, and a freshwater dip will help remove anything that can harm the fish or contaminate the tank water.
   • Add dechlorinated freshwater to a container, making sure that the pH and temperatures are as close as possible to those of the main tank.
   • Using a net, gently lower the fish into the freshwater dip and allow it to swim in the container for 3-4 minutes, watching the fish’s behavior closely. Remove the fish from the freshwater if it floats or stops moving and place it back into a quarantine tank.
6. Transfer the fish with a net. Once your new tropical fish has had a freshwater dip, it will be ready to be placed in the main tank. Gently scoop up the fish with a net.
7. Place the net in the tank. With the fish in the net, swiftly but smoothly dip the net into the tank. Hold the net inside the water until the fish swims out of the net.
8. Monitor the fish. As the new fish adjusts to its surroundings, be on the lookout for any signs of aggression, including chasing and nipping. Rearrange the plants and rocks in the tank to create new territorial boundaries if you see any signs of hostility or stress. If the aggression continues, place the aggressor in the quarantine tank for a half hour or so and return it to the main tank.

Tips

• Look out for any signs of disease or illness. If you notice your new fish is acting strangely, remove it from the main tank and place him in a quarantine tank where you can monitor its progress.
• Don’t overcrowd your tank. For every inch of fish in your tank, make sure you have at minimum one gallon of water.

Warnings

• Always cycle your tank before adding any fish! Check the pH levels and perform ammonia tests to check if water is safe for your aquatic critters.

Related Articles

• Set up a Tropical Freshwater Aquarium
• Treat Tropical Fish With White Spot Disease (ich)
• Avoid 'New Tank' Syndrome
• Transport Fish

Sources and Citations

See also

• Create Aquariums So Lizards and Fish Can Coexist
• Know Which Fish to Put Together in a Tank

What links here

• Set Up a Freshwater Aquarium
• Avoid 'New Tank' Syndrome
• Set up a Tropical Freshwater Aquarium
• Transport Fish