Hard to tell with the acei's. By the fins I would say male. (?)
http://www.cichlid-forum.com/profiles/species.php?id=1460

thanks Sandy, what do you think about this one, he/she is about 2 1/2 in

i always buy juvies, cant ever tell with these, its the 5th one i got trying to get females, they always turn out being males

Looking better @ that site if I were to bet I would have to say female. (but I wouldn't bet the house lol) I say that because the dorsal is rounded and not very long. The male pics seem to have dorsals that extend out to the tail fin. Check it out and see what you think

thats whai i noticed first, the dorsal fin is to the tail now and shes losing the yellow on top, i just dont have any luck with them, gonna have to buy adults i guess

Mo they are so hard to tell apart. I still have trouble sometimes telling Lily (my female) from her son who is the same size. I don't think you can tell by pointed or non pointed fins for acei though. My large male has really short rounded fins, and my female has short, but more pointed fins. I did notice one thing, my female's dorsal is all yellow, where as my males, the yellow is only towards the end of it. Here are some links to my male and female so you can compare...My male is around 6" and my female is about 4.5".
Male...

http://www.cichlids.com/pictures/pic/Purple_Haze_Feeling_Frisky.html

Female...

http://www.cichlids.com/pictures/pic/Purple_Haze_and_Lily.html

Hope it helps.

Nice