I used to have a fish tank when married, and after a few years I'm setting another one up, but my ex husband was more the expert. I'm trying to decide what fish to have. I saw some beautiful small orange fish, which later found out are live bearing Platy, so not so sure, as when we had live bearing guppies before they never stopped breeding and we didn't know what to do with the babies. I was wondering if just keeping males or females alone would make a happy fish family? No sexist jokes please about how they're better off, but seriously, is it better to keep males and females together? If so I might go for different fish less likely to breed.
Yes, you can have a single-sex group. Males may be more boisterous and aggressive with each other than females so personally I'd go for an all-female group - BUT, don't buy females from anywhere that keeps them in the same tank as males as the chances are they will already be pregnant!