I've had a Madarin and a Spotted Mandarin for little over a year now. Both in tanks with plenty of LR and copepods. When I purchased them at LFS, I asked LFS guy if he had any Mandrins that would take frozen brine. He fed them for me, they ate the brine shrimp, and I felt comfortable knowing that .. so I bought them.
They both are doing well, but do have special diet requirements.
Good luck ...
Broomer