Clownfish generally pair up quite easily but not always. Sometimes the smaller fish is killed before he is accepted by the female. Just make sure you get a juvenile clownfish because two females almost always means certain death. When you go to put the clownfish together I like to keep them separated, but allow them to see each other. I used an acrylic container that hangs on the side of the tank. For the first couple of hours she kept trying to attack him through the container, but she eventually warmed up to him. After about three hours I released him into the tank with the female, she initially went after him but soon after they fell madly in love!