Actually on this topic of tang size. My YBRT has usually been a model citizen. Sure there's some minor chasing from time to time but nothing that ever lasts long. Last night it was chasing my female Blue Throat Trigger relentlessly. I have a 10x8 mirror I tape to the glass when I add a new fish. It redirects attention away from the new fish. I put it up last night and I'm hoping this settles out but if not I may have to look at rehoming it if this continues. If I don't have any takers I have the option of donating it to the Georgia Aquarium. I'm hoping this doesn't continue, if it does I'll have to do something soon.
In tank the size your keeping you will absolutely need to buy the tangs at the same time and qt them together then add them to the display at the same time as well. They also need to be the last fish you get. If you don't do that one of them will surely not make it long. Another key is keeping them well fed. This means nutrients can become an issue for the system. Most if not all aggression is food related. A well fed tang is usually a well behaved fish. This means daily nori feedings in multiple places in the tank with more than one tang, if you don't do that the dominant one will absolutely become an *****. Then stress goes up, ich breaks out and in worst cases wounds from tail slapping.
If you're dead set on doing this I highly recommend one and no more than two of smaller size. With three your just asking to only have two at some point.
In tank the size your keeping you will absolutely need to buy the tangs at the same time and qt them together then add them to the display at the same time as well. They also need to be the last fish you get. If you don't do that one of them will surely not make it long. Another key is keeping them well fed. This means nutrients can become an issue for the system. Most if not all aggression is food related. A well fed tang is usually a well behaved fish. This means daily nori feedings in multiple places in the tank with more than one tang, if you don't do that the dominant one will absolutely become an *****. Then stress goes up, ich breaks out and in worst cases wounds from tail slapping.
If you're dead set on doing this I highly recommend one and no more than two of smaller size. With three your just asking to only have two at some point.