Adding 4 female Bettas to a new tank set up

[seasonkelly]

i need some advise. My son got a female Betta for Christmas last year and loved the fish so much, i got him a tank this year. i just set it up and have done some research about putting female Bettas together. i read you must put 4 together to keep them from killing each other. i have set up the tank and have not added the fish together yet, it is a 10 gal tank. THe main question i have is that the fish we already have is twice the size of the other 3 we just purchased and i was wondering if i should add them all at the same time or just the smaller ones and add the bigger one a little later after the smaller ones get use to the tank, find hidding places, etc. Or, i bought a divider, so would it possibly be better to seperate the larger one from the smaller ones at first and let them get use to each other before taking out the divider (of course you still do not have 4 that are really together). i have placed the new fish next to the older one and she is having a fit, so that makes me nervous that she will kill them or try to. She is in a bowl, btw. Also, i read to add 3 fish at first when breaking the tank in, but i also read that you should have more than 3 female Bettas to have a successful colony. i am confused as to what to do. Can anyone help me out??? THanks

[Oldman47]

Once the tank is done cycling, I would get all the real and fake plants and decorations in place. When everything is set up put all the smaller fish in together and let them settle in then put in the larger and older one. She will figure that she's the new fish on the block and probably not be too aggressive. All of the betta will chase and nip at each other the way many cichlids do. This will go on constantly in a female betta colony. This is nothing to worry about unless one of them decides it owns the whole tank. That is where having enough in the colony becomes important, it spreads out the aggression so that none of them are hurt too badly.