does anyone have any advice?

[fishwatcher]

I have 3 whiteskirts. I originally had just 2 and they got along ok, but I'd read where there should be at least 3 of them, so I got another one. Well, now they all constantly harrass each other, chasing and nipping any time one sees the other one. I wonder if I should take them all out and put them in a separate tank for just a little while, change the regular tank around some then add them all at the same time. Would that help them not be so nippy? I don't have room for any more of them, as you can see. What should I do?
I have noticed that the one with the least flowy tail is the meanest one. Is this a male or female? They seem to have taken territories too, but only bc the meanest one is making them, it seems.
Is this normal??
I'm concerned mostly bc the newest one only has the back corner to be in, and when I feed them I have to chase him from back there or he doesn't see the food.

 

[fishwatcher]

bump... please help

 

[Redbled]

Do you have plenty of plants and hiding spots. Some fin nipping with fish will always happen. I'm not sure I'd be overly concerned with it.

 

[fishwatcher]

It has quite a few plants, and a few terra cotta pots (caves). I wonder if they are different sexes. The 2 longer-tailed ones get along ok, but the shorter-tailed one won't let either of them come up front to eat. I have to scare them to the front. Should I just remove the meaner one?