So I found myself at the end of this weekend with 4 rams. They are now in the Angel tank along with some tetras. Anybody want to give me some advice on sexing these things. I think I already know of 2m and 1f the other is undetermined. I will try to get pics up soon. The 2 I believe to be males have a standoff in the center of the tank quite frequently and one of them always goes back to the corner with the female. The 4th fish minds his/her own business and hangs out with the pristella tetras. Any help on this would be appreciated. Any advice on keeping them would also be welcome.

I think with regular german blues only the females have purple bellies. I could be wrong though lol. Pics would help

Thank you. The one for sure has a really bright purple belly.

That is not a total guarantee! Sometimes really hard to sex until they breed.

I'm keeping 5 GBR's.. The males have a dominate front dorsal fin.. meaning the leading edge is quite a bit longer than the rest. The males of my clutch are more than fifty percent larger than the females. The females are less colored than the males. The bellies on my females are much like Kribs.. a pinkish color rather than purple but that could be attributed to water chemistry etc. Mine have spawned a number of times and in fact, when one pairs off and spawns, it spurs the other male to recipocate. I'm now at 4 false spawns. They are probably about 6 - 7 months old.
Update... In the last day or so, I've lost two of the three females. I suspect that they were over pursued in a 30G tank even though there is plenty of hiding spots.
I'll be holding off replacing the fems until I set up my 155G this week ... got a start tonight... and then setting up an additional 33L for the Rams... Oh.. picked up a Bolivian for 3.00 a few days ago.. Bill in Va.

Thank you all for the info. Once I get my stupid camera to work I will get pics. I have a couple pics on my phone but not worth posting they look so bad.

Still no pics but atleast I know there is a female for sure in the tank. A ton of eggs laid on a rock in the tank. However I have had one casualty which I believe was a female as well. I will update if things go right with them.