betta and large fancy goldfish

Question
I would like to if i could put a male bata in a tank with a big goldfish. the tank is a 30 gallon.?  I know that 2 male batas can not be together. research i have done has told me that it would be okay as long as the batta isn't with a fin biting fish. I have had bettas before and have always had females with my male. my brother is needing to get rid of his large goldfish, that is why i am asking. I have had Manny Betta fish and each fish i have had has lived for 2 years and longer. in the same water that isn't 80 degrees. i know everyone says that they like it warm but mine have always been fine. the goldfish is verry large not small. like i have said i have done alot of resursh myself. I have even called alot of pet stores. everyone thinks the goldfish would be fine.

Answer
Hi Cedar: no... please don't mix the betta with the goldfish... betta's are tropical fish and goldfish are cold water fish... so your betta wants to be in a tank of about 78-82 degrees and the goldfish wants to be in a tank between 50-72 degrees... if you mix the two you will end up with sick fish... let me know if you have further questions... dave