Depends on how long he is flaring, if it is a constant thing (more than 10-15 min at a time) you might consider covering 3 sides of the tank leaving only the front open for awhile. I used posterboard on mine. I left it that way for a week, then began uncovering one side at a time, waiting to see if he would flare, if he did I'd leave it open for around 10 min then cover it back up. It took me a couple of weeks to get it where I don't have to cover any of the side anymore. He'll occasionally flare at his reflection or the shrimp, but not took often.