Purple and Yellow Tang Cohabitation

[Gools]

IMO a 180 or large. I would either add them at the same time, or if one is already in the tank, then the other being put in should be large then the one already in there.

[Cap'n]

I wouldn't do it. Over time the purple is going to outgrow the yellow while also becoming more territorial. I would expect you would eventually need to remove one of the tangs.

[Jim Barry]

I have a Blonde Naso, a Yellow Tang and a Purple Tang in my 180g. They all get along fine, however the Purple Tang is the smallest.

If you decide to put the Tangs together, I would add the Purple Tang at the same time or later, definately not first

Jim

[Ruth]

I have a Hippo (Regal) and a yellow in my 230g and a Naso in my 190g. I wouldn't add any more tangs to either tank right now. The Naso is a honker and I'm told he will get even bigger. My yellow tang is very aggresive and would probably do OK with a purple tang but they are all different. Like the others have said make sure you have at least a 6' tank if you are going to try - and if you can catch him you are welcome to my yellow as I think he would hold his own with any other fish. JK I live too far away.

[props]

i have a yellow and a purple tang in my 90 for about a couple of months now
so far so good.

i know this is a no no but i have 5 tangs in my 92 and they all get along fine. hippo, kole, sailfin, yellow, and powder blue tangs.

[Chin_Lee]

There is a lot of factors to consider to mitigate. IE age, aggressiveness, size, and timing of the introduction to each other. There will always be people who can do it successfully and just as many who have not. I was always in the opinion that purple tangs are much more aggressive than yellows but I have seen many subdued species and many aggressive ones as well. I am ashamed to admit but I am one who have not succeeded several times in the past because my purple was very cunning and melicious. I have since been successful for the past 6 months with a highly aggressive yellow tang that will tell the purple to pound sand with attitude. (btw for the tang polices looking to flame me, go pound sand too because I'm posting my experience in hopes to benefit others)
I believe the older and larger either species are, the more problems you will have. But if both are introduced when small (2 inches or less), neither are mature yet and I believe will learn to co-habit with each other (i believe many species of juvenile tangs school in the wild until they get a little older for better chance of survival). That is (IME) one of the better methods to get them to be in the same tank together. When they start getting bigger, they are more unpredictable and lessor chance of success of cohabitation.
The cons to that method is that the smaller tangs' survival rate is not as good when smaller.
Hope that helps