Is this normal for balloon mollies?
Four-month old tank owner of freshwater fish. Have a 20 gallon with 4 guppies. 2 bubble bee mollies, a platy and 2 male/female balloon mollies.
Out of those, the balloon mollies are my favorite by far. Bought the male/female Nov 2 and they were peaceful in the tank. Just today I went and bought 2 more male/female - moments of introducing them to the tank, the two males attacked each other! I was horrified. It's about 7 hours later and every time I check on them, I see them at it! Am I going to find them dead tomorrow?? So upset! Was I wrong to add the 2nd pair? And the 2nd pair happen to be bigger in size, slightly.