Introducing New Fish into Your Aquarium

Have you ever moved to an area with a different climate? It might have taken you a while to get acclimated. The same holds true for fish when moving to a new aquarium. In fact, fish are very sensitive to their environments. Subtle changes in water temperature, pH and nitrates can affect your fish’s health and survival.

New additions to your tank can also affect your existing fish. To keep your aquarium healthy, we offer the following suggestions:

  • Research the new fish species – Is it compatible with your existing fish? How large will it grow? These are things you should know about any species you add to your tank.
  • Fish quarantine – One of the cardinal rules of fishkeeping is to quarantine new fish before adding them to an aquarium. Otherwise, you risk introducing a parasite or disease that could infect all of your fish.
  • Quarantine tank – A small 10- to 20-gallon tank with a basic setup is sufficient. Include a sponge filter, fluorescent lighting, a heater and plastic plants that will offer a few hiding places. It’s a little extra work, but this investment will protect your main aquarium in the long run.
  • Quarantine process – Fish should spend two to three weeks in quarantine before being transferred to the main tank. During this time, you should watch closely to make sure the new fish aren’t carrying parasites or diseases.
  • Test water quality of your main tank – When the new fish are ready for your tank, they should be transferred into water with the least stressful conditions. This means the chlorine level should be at zero and the pH and other levels should match those of the water holding your new fish.
  • Check the neighborhood first – Make sure your aquarium has plenty of hiding spaces for the new fish. Also, feed your existing fish so they’re less aggressive. Keep in mind, your current fish may still harass a new tankmate. To combat this, try to add more than one new fish at a time or rearrange tank decorations first to distract your current fish into establishing new territories.
  • Adding the fish – When adding the new fish from the quarantine tank or Pet Supermarket, first dim the lights in the tank and your room, then float the sealed bag with the new fish on the water’s surface. Let it sit for 10 to 15 minutes to adjust in temperature. Then open the bag and add half a cup of aquarium water to it. Reseal it and let it float. Add half a cup every 5 minutes. Once the bag is full, use a net to transfer the fish to your tank (don’t add the water from the bag into your tank). Keep your tank light off as your new fish explores his surroundings.

Watch your fish for signs of illness or aggression and enjoy the beauty of a thriving aquarium with different species! For advice on compatible fish species and aquarium accessories, visit your local Pet Supermarket.