I slavishly QT all my fish, and it is most discouraging to get a new fish through 4-8 weeks of QT disease free and up to weight only to have it beaten to death by the resident 'mob' in the display. This used to happen to me with some regularity until I adopted my current regimen. Haven't lost a new fish to resident aggression now in almost 5 years (have lost them for other reasons though). It's really just four things:
1. Ensure fish is at a healthy weight and eating before attempting to add it to the display; skinny fish and hiding aren't a combination for a good prognosis.
2. Use a socialization box (also called an acclimation box), and keep the fish in it for at least three days even if there is no observed aggression. Longer is fine.
3. Tape a good sized mirror to one end of the tank; in addition to distracting the more aggressive fish, it's quite comical to watch them posture for their reflections.
4. Release the new fish from the box after the lights have gone off and the 'mob' is sleeping.
There's nothing particularly revolutionary about these things; but they have worked really well for me. Doesn't eliminate aggression completely, but it reduces it enough for a positive outcome. Sequence/order of introduction helps in the early stages of a tank; but becomes impractical after that.
Any different or clever things that other folks are doing?
1. Ensure fish is at a healthy weight and eating before attempting to add it to the display; skinny fish and hiding aren't a combination for a good prognosis.
2. Use a socialization box (also called an acclimation box), and keep the fish in it for at least three days even if there is no observed aggression. Longer is fine.
3. Tape a good sized mirror to one end of the tank; in addition to distracting the more aggressive fish, it's quite comical to watch them posture for their reflections.
4. Release the new fish from the box after the lights have gone off and the 'mob' is sleeping.
There's nothing particularly revolutionary about these things; but they have worked really well for me. Doesn't eliminate aggression completely, but it reduces it enough for a positive outcome. Sequence/order of introduction helps in the early stages of a tank; but becomes impractical after that.
Any different or clever things that other folks are doing?