I have 4 mollies (2 male and 2 female) in a 16 gal tank with 2 female betta. I had no idea how quickly they would reproduce. I have atleast one pregnant female. From what I've read they can give birth monthly. I have 2 other tanks full of cichlids, so no place really to keep more mollies. How many can I have in the 16 gal tank with the fish I currently have in there?