Well i have four girls in my 20 gallon sorority that are getting along just fine with the harlequin rasbora tetras. (tetras and guppies arent really a problem with my bettas i have roger in the 17 gallon doing awesome!) And i was wondering if i could put roger in the 20 gallon and put the girls in the 17 gallon with the community. (basically the sorority with some buddies!) I counted and their would be exactly 17 fish. (1 gallon per fish. And i wont go over 17 fish for my 17 gallon) I was wondering if i could divide my 20 gallon for some males if i moved the girls. What do you think?