Mirror Trick on Gem Tang

[butcherreef]

I picked up a gem tang almost 5 months ago from a lfs for $400, which I believed was a great deal. The gem is a big fish around 5 inches. He has been in the tank since and is the only tang in the tank until 2 days ago. I picked up a biota yellow tang, because iv always been in love with a good yellow. I figured I have not seen any aggression in the gem tang to other fish since added so maybe I could give it a try. To be save I purchased a small fish trap and let the yellow acclimate in it for a week before releasing. The first hour all was well no aggression between the two and I was super stoked. However, the second the gem witnessed the yellow picking on his algae clip ww2 ended up starting. Since the gem is so much larger I figured the yellow will not be alive long. I ended up putting a mirror on the tank, after reading about success. I can tell you this does in-fact work wonders for now. The gem has been doing nothing but sizing himself up for hours, allowing the yellow to finally explore the tank. I am hoping when I take it off this zero aggressive behavior towards the yellow will continue but only time will tell. If any of you have any experience with this and know how long I should keep the mirror on for it would be appreciated.
I will also keep you updated on if this does in-fact work when removed in future posts to this thread if you would like to know.

 

[Reefering1]

Keep the mirror up until the aggressor stops attacking its reflection. 1-3 days is normal, ime, but pay attention. I may cut short if the fish is in there mirror day and night, not eating, for several days. This only happened once, and the cbb I was protecting was the only one still stuck in mirror. I took it down figuring he was ready. Worked out fine. How long has the gem been in there? Size of tank?

Edit- 5 months, I see it. So not thaaat established, but established enough

 

[Reefering1]

Adding multiple fish at a time also helps to disperse aggression. So tige established fish isnt only focused on one new fish

 

[nereefpat]

Adding a new tang of the same genus can be tough. How big is the tank?

 

[butcherreef]

4 ft wide, 105 gallon frag tank with a bunch of rocks, all the other fish are small 1 inch, including possum wrasse, Bengaii cardinals, 2 small clowns, royal gramma . I did end up removing the mirror after the gem tang and yellow tang were both directly next to each other attacking the glass. I watched for about an hour, and aggression is gone for now. We will see if it comes back, but they seem to be best buddy’s now. Feels like I just hotwired their brains.

 

[butcherreef]

Here is a picture of them hanging out now, I’ll get better ones if it continues in the morning.

 

[butcherreef]

I wanted to give a final update on this thread, since it has been a few weeks now.
The mirror trick I can say works like magic. I think it would be different if the tang added was larger. I believe the three days with mirror gave the small yellow tang a chance to navigate the tank without threat. The yellow has learned all the spots to evade the larger gem tang, and I barely see any aggression at all anymore. There is some small chasing here and there but the yellow can out swim and out maneuver the larger tang within the rock-scape. They both swim by each other with no aggression all day long.
Here are some pictures of how fat the yellow has got now that he is relaxed in the tank.