Fish Compatibility Query

I think it would be OK alone - this is a fish that likes to choose it's own mate so getting a male and female which don't get on would be worse.

Was the fish a standard ram or one of the selectively bred version (eg electric blue, gold, balloon, long finned etc)? The more 'standard' the fish the greater the risk of it having recent wild ancestors. The 'modified' forms have been tank bred for many generations to get the fancy versions and are less likely to have recent wild ancestors. This is important as tank bred fish are more tolerant of a wider range of conditions, including temp, than wild caught fish. With your water, there's no problem with hardness, pH etc it's just the temp. Wild caught fish need 27 to 30 C.  Harlequins range is 22 to 25; x-rays' is 24 to 28.



As a side note I have just learned that Fishbase is the best source for things like temp, that's where those numbers came from. When they give temps, someone actually measured the source water of the fish. The site is primarily a university resource; it was not designed for the general public though we can, of course, access it.