When you buy new fish at your local pet store, they may or may not tell you how to introduce your new friends to your fish tank. There are several steps that you can take to help insure your new fish's health and make the transition to the new fish tank less stressful for your new fish. Fortunately, alleviating - or eliminating - this stress to your new fish when you introduce him to your fish tank is quite simple.
1. The first step is the trickiest. Keep the fish someplace dark for the trip home. Hopefully the pet store will put the fish in his little clear bag into a paper bag or at least an opaque plastic bag. Hiding the moving world around him and keeping things dark will reduce the stress of the trip home itself. And, of course, get home as quickly as reasonably possible and safe. Don't run other errands on the way home with your new pet fish. It is normal for a new fish to lose a lot of color during the trip home. Don't worry about this, your new pet fish will recover quickly.
2.. When you get home with the fish, put the plastic bag holding the fish in your aquarium and let it floatunopened for fifteen to twenty minutes.
3. You may want to take some of this time to re-arrange the decorations in your tank. Moving things around will help to break up the territories of fish you already have, which will result in less fighting as the new fish try to find their place in this small world.After the bag has been floating in the tank, and the water temperature has stabilized, acclimating the new fish to the tank's temperature,
4. you are ready for the next step. DO NOT MIX THE WATER FROM THE STORE INTO YOUR TANK!!! Carefully open the bag and scoop an equal amount of water from the tank into the bag. (You will need to use a cup or something.) There should now be about twice as much water in the bag as the pet store gave you. Let the bag float in the tank for another fifteen to twenty minutes. You will probably need to close the hood on an edge of the bag to keep it from spilling its contents into the tank.
5. After the bag has rested again (another 15-20 minutes) and your fish are getting really anxious to get out of it into the tank, you are ready to release them. Again, remember to prevent the stores water from getting into your tank. Carefully net the fish out of the bag one at a time and place them gently into the water of your aquarium.
6. Now, sit back, relax, and enjoy!