combining fish

Question
Hi, I have one goldfish right now.  A friend of mine is giving me his 35 gallon gallon with fish.  Here is the list of fish in his tank: two plecostimus, two tetras, a mickey mouse platy, and a gourami.  Can I combine his fish and my goldfish?
Thank you

Answer
Hello Irene,
The short answer is no. I definitely do not recommend it.
Long Answer: Not only do these fish differ in so many ways, and come from different parts of the world, but they also have different needs when it comes to food and temperature. It will be rather difficult to find a happy medium in temperature for both cold water and tropical fish in the same tank. Also, you may have a tough time trying to get all the fish the right food, as tropical fish should NOT eat goldfish food, and vice versa. They do have different dietary needs. Lastly, this may be just a bit too many fish for a 35 gallon tank. Your Plecostumus will grow up to 24 inches long each, so they really should be housed in at least a 55 gallon. The tetras, platies and gouramis should be fine with a few other fish added, as long as the filter is decent and you keep up on your weekly water changes and quality tests.
Please do take some time to research tropical fish care before receiving the tank from your friend....as there is MUCH to learn!
Hope this helps!