I don't know about a /meandering/, but I doubt that bottled zooplankton would help a /mandarin/. I think there's a sticky somewhere about mandarin and other dragonet care. Since dragonets spend most of their time living on rocks/the solid parts of our tank, and not in the water column, it seems unlikely that zooplankton (floating food) would provide much nutritional value. Mandarins eat things like copepods, amphipods, mysid shrimp, and other bottom dwelling stuff.