There's no need to argue about these things! That's the whole point of asking, because you don't know! Silly people lol
haha NO I wasn't arguing with MissRuthless , I actually agree with what they said. I was saying that I've gotten into some arguments with other users because they believe goldfish can be kept at 76f and above which is some what true but for a short period of time, long term it could have terminal effects on the Goldie, they shouldn't be kept at anything above 70-72f.
but in your situation your tetra can't be kept at the goldies natural water temp, so that's why to reach a some what ideal temp for both would be around 72-74f.