To me it looks to small from the pictures for proper venting. Yeah, better pictures would be best.
Looks like all males judging from the video. In my opinion and the angles I'm seeing the fish. You should try a close up video .just moved them to a new tank, colors a little faded still from the move. I broke the main light on the aquarium, so please forgive the poor lighting.
heres a rather long video

thank you, the larger one of the 3 is showing some weird pattern/bars most of the time.Man those carpintis are beautiful