Ive had had a spotted mandarin for about 4 months and he was "supposedly" tank bred and eats frozen. He just goes around all day picking and picking but I've never actually seen him chase frozen but he has been plump so I wasn't too concerned. I then bought a orange spotted goby to sift and clean up my sand some and have noticed that the mandarin has slimmed down quite a bit. Do you think the orange spotted is cleaning the sand too much to the point that the mandarin has nothing?