I just signed up here... new to all of this. I have a 75 gallon tank. I just bought a 5 inch red belly about a week ago. He is the only fish in the tank. He is pretty cool but I was wondering if I could still add one more. I wanted to go with only one at first because I didn't want them chewing on one another. But one is just so boring. Is it to late to add another?? Plus what are some good tips for them not to fight and eat each others tails all the time?? I just don't want them all beat up all the time. Thanks for the replies!! You guys seem to know what you are talking about.