Have two mated clowns and a a Lubbocks Fairy wrasse in my 40 breeder. They have tortured and killed 4 green chromis, algae blenny and bi-color blenny. Thinking about removing them and going with mellower fish.
Last week I used the mirror trick. Worked fantastic. The fish were so angry with themselves that didn't realize of the new guy. 24 hours later the new guy was fighting with himself.... LOL....so I took the mirror out.