Another reason for choosing mollies over damsels is that they are hardier. Not all damsels make it through the cycle. Mollies have a better survival rate. Some like to put the mollies in the hospital tank after their main tank cycles so their hospital tank remains stable. Also, don't forget to acclimate the mollies! They are freshwater fish that can thrive in saltwater, but they need a special acclimatization period when you switch them to saltwater. I can look up more info on this when I get home if you want.