Can you introduce new fish into a tank with old fish already in there?

[Joy]

I have a fish tank with one goldfish and 2 rainbowfish in there already. I want to get more fish, is it possible?? Will my old fish attack the new ones??

 

[Slim]

yes of course, but i suggest you put them in a smaller tank inside the water so the others can get used to them....or keep them in the bag hanging off the edge but in the water....

 

[Spunky Ninja Style]

Goldfish are extremely peaceful and not likely to attack other fish, but they should really be kept in a species-only tank. Rainbow fish are also peaceful and would not likely attack other fish. Make sure that if you introduce a new fish into this tank that you get a peaceful type of fish, and stay away from the semi-aggressive or aggressive species. If you are in doubt, you can ask a petstore employee, but I wouldn't always go off of their word. They don't always know (especially at the chains) - you are better off getting multiple opinions and researching the new fish online first.

 

[FishLover24]

You can add onother of either of the current fish you have but you'll have to check for other fish.