Powder Brown Tang / Powder Blue Tang & tank buddies

[Laranda_C]

This is going to be a multi-part question...
My husband went to our LFS a couple of weeks ago and brought home a powder blue and a powder brown tang.. The powder blue is a little smaller than the brown. The LFS owner had told him that she had never had any issues with the two together as long as we QT'd together and added them together (after reading all of the stories online, I'm not sure that's 100% true). We QT'd them in a 29 gal tank together with plexiglass with holes in between them.. while in QT they did act anxious at first, but eventually calmed down after a few days. We removed the plexiglass on the last day & they swam around together and didn't seem to have any major aggression issues. We went ahead and added them into my 180 gal DT that next day. 1st day was fine.. on the second day they began chasing each other around the tank and doing their dance in circles. 3rd day the powder brown seemed to be doing most of the running... He would run the powder blue to the corner of the tank. The powder blue would not back down, it kept swimming into the corner, but every time it would come out it would charge after the brown... over and over and over again. Within 6 hrs on the 2nd day they both had white specks all over and I freaked out because I had dealt with velvet before and that was traumatizing yo myself and my wallet. I read that it could be from stress (no other symptoms, they were eating fine and all of my other fish looked fine.) We gave them one more day to calm down, and when they didn't, we removed them & put them back into QT tank together with plexiglass between. The next day they are completely spotless and calm.

Should I surrender one of the tangs and maybe swap for a different kind?
Or does anyone think i should give them time and try again?
If I do surrender one and get another, which tang would do best with a powder brown?

Inside the tank I have lots of live rock, a few soft corals, conch snails, 1 cleaner shrimp, 1 coral beauty, 1 false lemon peel angel, two clowns, & 3 wrasse.

 

[Gundy]

Both fish can be very aggressive and it sounds like the powder blue is the most aggressive of the 2. My guess is that they will never get along and will only result in tragedy. If the powder blue is that aggressive, it may attack other tangs in the future. I would keep the powder brown and remove the powder blue. Hopefully the powder brown will be more tolerable to other tangs in the future.

 

[Uncle99]

If there’s no physical damage being done, I’d see if they can work that out themselves.

 

[ScubaSkeets]

Were they in the same tank at the LFS? I bought my Powder Blue and Powder Brown from my LFS and they were both QT'd and displayed in the same tank, as well as acclimated at home in the same tank. Been over two months and there is no aggression and no signs of stress (ich). They pretty much ignore each other but sometimes they'll pal around. The Blue is about 3/4 the size of the Brown and i dont know if things would be different if the sizes were different.
Perhaps try a mirror against the glass and maybe the aggression will subside?
I also feed somewhat heavy so there's no competition for food, and also feed them Nori.

 

[Crabby48]

they both may settle as neither back down but most likely it will begin again as they mature and at that point it may be to late.

You said you qt’ed them so how do you see spots? If ich or velvet is in the tank or on fish it will show when the fish are stressed like them not getting along