Guppies and endlers are both very comfortable with the real needs of mollies. If you have fallen for the idea that mollies need salt then you can forget both guppies and endlers in that tank. The real needs of mollies is hard water with a pH of well over 7.0. They also appreciate a diet high in vegetable matter. I keep mine at 7.8 pH and they prosper and reproduce like crazy. I even sold some today at a good price at a fish club auction although they were only 2 months old. Mollies kept properly are tough little fish that are a joy to watch. They exhibit lots of personality and will try to interact with you when you come near the tank. That was the way that I caught the fish so easily to take them to auction.