saboy
Fishaholic
I take it your in america ?
new jersey, for you saboy just incase lol.
btw the dorsal fin is the fin along the fishes back, in males the end is more pointed than the rounded females.
but with pics we can help you.
samUK, you could just wait until they spawn and look at which lays the eggs....
generally fins are longer and more pointer in males like the anal fin which you said was the only reliable way......
and as for nuchal humps, i have seen females with them they can be reliable depending on species.
i dont know what ph is and when people say the water has to be hard