Have you made a fish list? It's common that people go for clowns first but I think you should make a fish list and start with most docile to most aggressive/territorial. Clowns range from medium to high aggressive fish imo.
Also don't put any CuC for a week after introducing the fish. See if fish picks up food from sand n rocks. If they do your CuC won't have enough food to survive.
Also don't put any CuC for a week after introducing the fish. See if fish picks up food from sand n rocks. If they do your CuC won't have enough food to survive.