I didn't mean to sound so snippy. Sorry. No, I was saying I was hoping you put that up to teach people what not to do with all the info you used and hoping it wasn't meant to rile up people intentionally, that's all. =p They like it nice and hot, well, warm...compared to some fish they like it hot and enjoy temps as high as 90F, though it's best to set it around 80 or so, otherwise their metabolisms spike.
You should try again, if you're willing, but don't put two together, not even male and female as they will still fight eventually, may even right off in many cases. They're nice hardy fish, but it's a common belief that they like small spaces and don't need a heater or filter. And it's not always the buyers fault since MANY ask info before getting them, and very often pet shops tell you, quite energetically at that, that they not only don't need filters and heaters, but do great in bowls and vases(often recommending toxic plants) and don't like temps higher than 70 degrees. I chowed down on a pet shop worker who did this to a sweet elderly couple asking about it(even told them to put two males together provided the tank was ten gallons or more and said they'd do fine in that much space, which is false since you could put two males in a very well planted 100 gallon tank with no other fish and they'd still find each other and fight), they came to me for info on it and the petshop girl flushed and fled.
I feel bad, I am sorry I came off so harsh! I suppose I get a little rough when it comes to care, not always remembering that it is NOT always the buyers fault, nor do I MEAN to sound so harsh. Many get advice from the wrong place is all, and don't know better. So I apologize for sounding so snappy. It wasn't meant to, honest.
I am sorry for your loss. =( It's not fun to lose any pet, even fish, when you try to give them a good home.