Copperband; Aptasia bloom

[htfn]

I have an aiptasia problem, too and bought two peppermint shrimps last week, but only last for a few days. I tried couple times with shrimp but always eaten by something in my tank. I also tried copperband, but yellow tang was attacking it, and died. I never sucsess with any chemical. It just comes back more and more after injection. Anybody have any idea what is my next hope? I am thinking to try filefish but I don't know, my current fishes like it. My fishes are yellow tang, six line wrasse, maroon clown, bangai cardinal and banded pipefish in 90 gal tank.
Thanks