I bought a tank divider for my exact tank. It kept twisting at the bottom allowing the fish to back back and forth.
I ended up returning the tang to a lfs for store credit. I got what i paid for it and he will be happy in the huge frag tank he is housed in now.
Now, i will see if the cb angel starts to improve. Thanks for all the help Beth.
All fish are now out of qt and hypo. The CB angel color has brightened and is claiming his own territory in the rock work and caves. i did observe him eating a little today when i fed the tank.