Right now I have 12 females, 7 are already a group (they are sisters) and 5 are not. The 7 are in a 15 gallon, 1 is in a 5 gallon and the other 4 are in temporary 2 gallons.
I have a 20 gallon I want to use to introduce all of them to each other at once.
And when they are all good with each other, I want to buy a 50 gallon to decorate and make a 'betta heaven' to have them live in that.
But right now... What's the best way to introduce them with each other, a way that has the highest succes rate?