While your tank finishes maturing, you should put the final touches on your shopping list of fish. You should have already determined how many fish will fit in your aquarium, and consider what type of fish you will buy. You may want to visit your local fishy dealer and see what they have to offer, and what they suggest for the environment you have created in your aquarium. You can also put down a deposit or pay in advance for fish that you want and have them set aside for you to pick up when your tank is ready.

You will want to decide also at this time if you are going to introduce your fish to the aquarium all at once or in stages. It can be best in certain situations to introduce fish one at a time, particularly if you are going to be buying adult fish or marine fish. However, adolescent fish can often be introduced all at the same time. Keep in mind that the filter will need to adjust for the added volume of the tank with the fish in it, and you don’t want to overload it too quickly.

Buying a fish is very stressful for the fish. Being caught, bagged, transported and released into a new environment is very stressful. And stress can kill a fish. Therefore it is important to take some cautionary measures to try to make the transition as stress-free as is possible. One way to do this is to put the polythene bags into brown paper sacks so that the fish is not overwhelmed by its surroundings during transport.

Be aware that will fish are meant to live together. Always surprised by the number of people they will going to a fish shop, by 10 different fish from five or more different tank is in the shop and then place in a single tank and just assume they will all get along. The fish in the pet shop and not just in different tanks to display reasons. Often they are in different tanks because one species doesn’t like the other because the size difference between the fish means one is Hunter and one is pray.

If you’re not careful with the fish breeds you decide to mix in a single tank one of three things is going to happen when you introduce them all into the one tank

  1. There will be immediate violence resulting in the death of one or more of your fish.
  2. There will be ongoing violence resulting in a gradual reduction in the numbers of your fish.
  3. The increased stress on some of your fish due to the worrying activities of the more aggressive breeds resulting in your fish survival rate over time being lower than it should be.

Speaking of transport, how you transport your fish is very important as well. You will want to have your fish double bagged and have the space filled with oxygen if you are travelling some distance before getting to the aquarium. If you are getting larger fish you will need some type of bucket with a lid that you can transport them in.

When you get the fish home you need to keep in mind that transferring the fish from bag to aquarium need to be kept as low stress as possible. Do not over-handle the fish. Take out one bag at a time. Place the bag on the surface of the water in the aquarium so that the temperatures can equalize. The longer the fish is floated the higher the stress, so it is important to do this for a few minutes only. Submerse the bag to allow the fish to swim out freely

Remember your fish will be frightened and confused, and there are many things you can do to make life easier for them during this transition. One thing you can do is turn off the tank light and minimize the light being let into the room with the aquarium. Don’t try to feed your fish for the first twenty-four hours as well.

When you introduce subsequent fish, you should start with a quarantine tank so that you can make sure there are no diseases being transferred the fish you already have. The quarantine period should last two to three weeks. The temporary tank should be matured just like your main tank, but the water chemistry should be what the fish is used to. You can change it gradually during the quarantine period to match that of your main tank.